8th grade - njctl
TRANSCRIPT
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8th Grade
Data
2015-11-20
www.njctl.org
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click on the topic to go to that section
Table of Contents
· Two Variable Data
· Determining the Prediction Equation
· Two-Way Table
· Line of Best Fit
· Glossary
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Two Variable Data
Return toTable ofContents
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Two Variable Data is also called
Bivariate Data
With bivariate data there are two sets of related data that you want to compare.
Two Variable Data
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Example 1: An ice cream shop keeps track of how much ice cream they sell versus the temperature on that day.
Temperature degrees F
Ice Cream Sales $
57.5 215
61.5 325
53 185
60 332
65 406
72 522
67 412
77 614
74 541
64.5 421
This table shows 10 days of data.
The two variables are:Temperature and Ice Cream Sales.
We can create a scatter plot by plotting the points.
Temperature is the x variableSales is the y variable.
Scatter Plot
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Ten Days of Ice Cream Shop Sales
Temperature degrees F
Ice
Cre
am S
ales
$
Scatter Plot
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What did the scatter plot show us?
Using the Scatter Plot it is easy to see that:
warmer weather leads to more sales.
Scatter Plot
click to reveal
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Scatter Plots are either:
Linear Non-linear
Scatter Plot
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These scatter plot are also non-linear.
Scatter Plot
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If a scatter plot is linear it can be described 3 ways:Negative AssociationPositive Association
No Association
Scatter Plot
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1 What type of scatter plot is shown from the Ice Cream Shop example 1?
A non-linear
B linear, positive association
C linear, negative association
D linear, no association
Temperature degrees F
Ice
Cre
am S
ales
$
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Example 2: Data for 10 students math and science grades are shown in the table. Plot the points to create the scatter plot.
Math Grade
Science Grade
56 6296 9385 8184 8263 60
100 9878 8189 9146 4875 75
Math Grades
Scie
nce
Gra
des
Scatter Plot
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2 What type of scatter plot is shown for the math and science grades from example 2?A non-linear
B linear, positive association
C linear, negative association
D linear, no association
Math Grades
Scie
nce
Gra
des
Click to reveal solved graph.
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3 What kind of association is shown in the graph?
A non-linear
B linear, positive association
C linear, negative association
D linear, no association
Time spent studying
Test
Sco
re
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4 What kind of association is shown in the graph ?
A non-linear
B linear, positive association
C linear, negative association
D linear, no association
Shoe size & Height
shoe size
heig
ht in
in
ches
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5 What association is
shown in this graph?
A non-linear B linear, positive correlation
C linear, negative correlation
D linear, no correlation
Height in inches
Wei
ght i
n P
ound
s
Boy's Height and Weight
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6 Which of the following scenarios would produce a linear scatter plot with a positive correlation?
A Miles driven and money spent on gas
B Number of pets and how many shoes you own
C Work experience and income
D Time spent studying and number of bad grades
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7 Which of the following would have no association if
plotted on a scatter plot?
A Number of toys and calories consumed in a day
B Number of books read and reading scores
C Length of hair and amount of shampoo used
D Person's weight and calories consumed in a day
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What kind of predictions can you make
from looking at the graph?
Predictions
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Number of Hours
Resting Heart Rate
12 616 7810 700 9016 652 854 7514 623 781 878 69
Survey Data
A student wanted to find out if there was a relationshipbetween the number of hours a person exercised in one weekand their resting heart rate. 15 people were surveyed and the table at the right shows the results.
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Plot the results of the survey on
a scatter plot.Number of
HoursResting Heart Rate
12 616 7810 700 9016 652 854 7514 623 781 878 69
Scatter Plot
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Linear Relationship? Association?
Is there a linear relationship?
Is there a positive or negative association?
According to your scatter plot, does a person who exercise generally have a lower resting heart rate than a person that doesn't exercise?
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Hours Math Grade
2 967 754 861 94
0.5 978 702 903 8710 681 946 754 88
Sandy wanted to find out if there was a relationship between the number of hours a student spent browsing the Internet ineach day and their math grades for the marking period.She surveyed several students and the results are shownin the table at the right.
Survey Data
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Look at your results. Is the scatter plot linear or non-linear? Is there a positive or negative association?
What can you say about the math scores as more hours are spent browsing the Internet?
Linear Relationship? Association?
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YearTemperatur
e in F
2,000 30.42,001 30.12,002 37.32,003 26.72,004 24.82,005 30.32,006 38.92,007 37.12,008 34.52,009 27.32,010 31.4
The table shows average temperatures for the month of January in New Jersey from 2000 to 2009.
Is it linear?Is there a positive association,negative association, or neither?
Linear Relationship? Association?
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MonthTemperatur
e in F
1 35.42 38.83 49.84 52.85 65.36 70.27 78.28 759 67
10 5711 4912 40.8
The table shows average temperature by month for New Jersey. Month 1 = January, Month 2 = February, etc.Make a scatter plot using the data from the table.Is the graph linear? Is there an association?
Linear Relationship? Association?
Ans
wer
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Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
8 What association is shown in this graph?A non-linear B linear, positive association
C linear, negative association D linear, no association
Shoe Size
Girl's Height in
Inches5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Ans
wer
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Poll 10 girls and 10 boys from your class on their heights and shoe size. Make a scatter plot for your observations.
Girls Height (in inches)
Shoe Size
Boys Height (in inches)
Shoe Size
PollTe
ache
r Not
es
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Wake Up Time
How Long to Get Ready
Survey your classmates and to find out what time they wake up on a school day and how long it takes them to get ready. Make a scatter plot of your results.
Is there an association with the time a student wakes up and how long it takes them to get ready?
Survey
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Line of Best Fit
Return toTable ofContents
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Line of Best Fit
Bivariate data plotted on a scatter plot shows us negative or positive association (correlation).
A line of best fit, or trend line, can help us predict outcomes using the data that you already have.It is drawn on a scatter plot that best fits the data points.
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Line of Best Fit
Notice that the points form a linear like pattern. To draw a line of best fit, use two points so that the line is as close as possible to the data points.
Our line is drawn so that it fits as close as possible to the data points. This line was drawn through (35,82) and (50,90).
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Time spent studying
Test
Sco
re
Line of Best Fit
Predict the test score of someone who spends 52 minutes studying.Predict the test score of someone who spends 75 minutes studying.
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Shoe size & Height
heig
ht in
inch
es
shoe size
Draw a line of best fit, or trend line, on this graph.
Predict the height of a person who wears a size 8 shoe.Predict the shoe size of a person who is 50 inches tall.
Line of Best Fit
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9 Consider the scatter graph to answer the following: Which 2 points would give the best line of fit?
X Y3 9
4.5 8
5 76 58 49 310 1
B
CD
A
A A and D
B B and C
C C and D
D there is nopattern
Ans
wer
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10 Consider the scatter graph to answer the following: Which 2 points would give the best line of fit?
X Y5 26 47 38 4
9 4.5
9 510 3
A
CB D
A A and D B B and C C C and D D there is no
pattern
Ans
wer
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11 Which two points would you pick to draw
the line of best fit?
D
X Y
2 96
7 75
4 86
1 94
0.5 97
8 70
2 90
3 87
10 68
1 94
6 75
4 88
B
C
AA A and B B B and C C C and D D A and D
Ans
wer
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Shoe Size
Girl's Height
in Inches
5 555.5 548 64
7.5 659 706 52
7.5 638 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
A
B
C
D
12 Which two points
would you use to
draw the line of
best fit?
A A and D B C and D C B and D
Ans
wer
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13 A scatter plot is shown on the coordinate plane.
Which of these most closely approximates the line of best fit for the data in the scatter plot?
A
B
C
D
From PARCC EOY sample test non-calculator #15
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Line of Best Fit
Using the scatter plot you created for shoe size v. girls' heights and shoe size v. boys' heights, determine line of best fit that goes through each of these scatter plots.
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Determining the Prediction Equation
Return toTable ofContents
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Line of Best FitThe points form a linear like pattern, so use two of the points to draw a line of best fit.
Our line is drawn so that it fits as close as possible to the data points. This line was drawn through (35,82) and (50,90).
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Use the two points that formed the line to write an equation for the line.
Find m Find b
Prediction Equation
This equation is called the Prediction Equation.The slope also shows that a student's score will increase by 8 for every 15 minutes of studying they do.
Where S is the score for t minutes of studying.
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Prediction Equations can be used to predict other related values.
If a person studies 15 minutes, what would be the predicted score?
This is an extrapolation, because the time was outside the range of the original times.
Prediction Equation
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If a person studies 42 minutes, what would be the predicted score?
This is an interpolation, because the time was inside the range of the original times.
Prediction Equation
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Interpolations are more accurate because they are within the set.
The farther points are away from the data set the less reliable the prediction.
Using the same prediction equation, consider:
If a person studies 120 minutes, what will be their score?
What is wrong with this prediction?
Prediction Equation
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If a student got an 80 on the test, What would be the predicted length of their study time?
The student studied about 31 minutes.
Prediction Equation
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14 Consider the scatter graph to answer the following: What is the slope of the line of best fit going through A and D?
X Y3 95 76 58 49 3
10 1
A
D(9, 3)
(3, 9)A
B
CD
Ans
wer
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15 Consider the scatter graph to answer the following: What is the y-intercept of the line of best fit going through A and D?
X Y3 94.5 8
5 76 58 49 310 1
A
D
(9, 3)
(3, 9)A 9
B 10
C 11
D 12
Ans
wer
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16 Consider the scatter graph to answer the following: The equation for our line is y = -1x + 12. What would the prediction be if x = 7? Is this an interpolation or extrapolation?
X Y3 94.5 8
5 76 58 49 310 1
A
D
A 5, interpolation
B 5, extrapolation
C 6, interpolation
D 6, extrapolation
Ans
wer
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17 Consider the scatter graph to answer the following: The equation for our line is y = -1x + 12. What would the prediction be if x = 14? Is this an interpolation or extrapolation?
X Y3 94.5 8
5 76 58 49 310 1
A
D
A -4, interpolation
B -4, extrapolation
C -2, interpolation
D -2, extrapolation
Ans
wer
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18 Consider the scatter graph to answer the following: The equation for our line is y = -1x + 12. What would the prediction be if x = 11? Is this an interpolation or extrapolation?
X Y3 9
4.5 8
5 76 58 49 310 1
A
D
A 1, interpolation
B 1, extrapolation
C 2, interpolation
D 2, extrapolation
Ans
wer
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19 In the previous questions, we began by using the table at the right. Which of the predicted values: (7,5) or (14, -2) will be more accurate and why?
A
B
C
D
X Y3 9
4.5 8
5 76 58 49 310 1
(7,5); it is an interpolation.
(7,5); there already is a 5 and a 7 in the table
(14, -2) it is an extrapolation
(14, -2); the line is going down and will become negative
Ans
wer
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20 What is the slope of this best
fit line that goes through
A and C?
A
B
C
D
X Y3 6
2 5
5 9
4 8
1 3
6 10
7 12
9 14
C
A
Ans
wer
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21 What is the y-intercept of
the line of best fit that goes
through A and C?
A
BC
D
C
A
X Y3 6
2 5
5 9
4 8
1 3
6 10
7 12
9 14
Ans
wer
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X Y3 6
2 5
5 9
4 8
1 3
6 10
7 12
9 14
22 The equation for the line of best fit
is . What would the prediction be if
y = 4.5? Is this an interpolation or
extrapolation?
A 8, interpolation
B 8, extrapolation
C 6.5, interpolation
D 6.5, extrapolation
Ans
wer
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X Y3 6
2 5
5 9
4 8
1 3
6 10
7 12
9 14
23 The equation for the line of best fit
is . What would the prediction be if
y = 8? Is this an interpolation or
extrapolation?
A
B
C
D
interpolationextrapolation
interpolation
extrapolation
Ans
wer
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Shoe Size
Girl's Height
in Inches
5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
Prediction EquationCalculate the prediction equation using the two labeled points.
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Shoe Size
Girl's Height
in Inches
5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
24 What is the slope of the
prediction equation
for this graph?
Ans
wer
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Shoe Size
Girl's Height
in Inches
5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
25 A girl with a size 7 shoe
and height of 56 inches
will be an interpolation.
True
False
Ans
wer
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Shoe Size
Girl's Height
in Inches
5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
26 A girl with a size 4 shoe
and height of 51 inches
will be an interpolation.
True
False
Ans
wer
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Shoe Size
Girl's Height
in Inches
5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
27 What will the height be
of a girl with a size
8.5?
Ans
wer
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Shoe Size
Girl's Height
in Inches
5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
28 A girl with a size 10 shoe
and height of 71 inches
will be an extrapolation.
True
False
Ans
wer
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Shoe Size
Girl's Height
in Inches
5 55
5.5 54
8 64
7.5 65
9 70
6 52
7.5 63
8 66
Shoe Size v. Girl's Height
Shoe Size
Hei
ght i
n In
ches
29 Using the prediction
equation, what will the
height be of a girl
who has a size
10 shoe?
Ans
wer
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Prediction Equation
Using the scatter plot you created for the shoe size v. girls' heights and shoe size v. boys' heights from your class, determine the prediction equation for each graph.
Using the equation, how tall is a girl that wears a 9.5 size shoe?
How tall is a boy that wears a 6.5 shoe?
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Two-Way Tables
Return toTable ofContents
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
Two-Way TablesWe can also organize data gathered in a two-way table.
Two-way tables display information as it pertainsto two different categories.
Here is an example of a two-way table:
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Two-Way Tables
What does the two-way table show us?
The table below shows information gathered from 30 students. They were asked if they took a bus or a bicycle to school.
Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
As you can see from the table, some students take the bus,other students ride their bicycles, take the bus or ride a bicycle to school. Several students do not take a bus nor ride their bicycles to school.
Two-Way Tables
Let's answer some questions using the data from the table.
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30 From this table, how many students take the bus
or ride their bicycle to school?
Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
Ans
wer
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31 How many students take the bus, but do not
ride their bicycles to school?
Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
Ans
wer
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32 How many students do not take the bus to school?
Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
Ans
wer
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33 How many students ride their bicycles to school,
but do not take the bus?
Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
Ans
wer
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Henry surveyed students from several classes to find out if they did chores and received an allowance. 65 students did chores. Of those 65 students, 49 received an allowance. There were 26 students that did not do chores and did not receive an allowance. 10 students that did not do chores, but received an allowance.
Set up your table, and label the categories.
Allowance No Allowance Total
Chores
No Chores
Total
Two-Way Tables
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Two-Way Tables
Allowance No Allowance Total
Chores 65
No Chores
Total
65 students did chores. Where would you write that number?
Notice that the "Chores" and "No Chores" categories are in the rows, and the "Allowance" and "No Allowance" categories are in the columns.
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Two-Way Tables
Allowance No Allowance Total
Chores 49 65
No Chores
Total
Of those 65 students, 49 received an allowance. Where would you write the 49?
Look at the "Chores" category, then "Allowance" since the 49 students who did chores received an allowance.
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Two-Way Tables
Allowance No Allowance Total
Chores 49 65
No Chores 26
Total
There were 26 students that did not do chores and did not receive an allowance.
Look at the "No Chores" category and "No Allowance" category.
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Two-Way Tables
Allowance No Allowance Total
Chores 49 65
No Chores 10 26
Total
10 students that did not do chores, but received an allowance.
Look for the "No Chores" category then "Allowance" category.
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Allowance No Allowance Total
Chores 49 65 - 49 = 16 65No Chores 10 26 10 + 26 = 36
Total 49 + 10 = 59 16 + 26 = 4265 + 36 = 101 or
59 + 42= 101
If you did your math correctly, the total row and column should be the same.
Two-Way TablesThis is the table filled using the information that was given. Although some of the cells are not filled, you can easily find the rest of the information with simple math.
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Allowance No Allowance Total
Chores 49 16 65No Chores 10 26 36
Total 59 42 101
Two-Way Tables
Here is the final table. Now you can answer some questions using the data.
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34 How many students took this survey?
Allowance No Allowance Total
Chores 49 16 65No Chores 10 26 36
Total 59 42 101
Ans
wer
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35 How many students do chores, but do not receive an allowance?
Allowance No Allowance Total
Chores 49 16 65No Chores 10 26 36
Total 59 42 101
Ans
wer
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36 How many students do not do chores, but still receive an allowance?
Allowance No Allowance Total
Chores 49 16 65No Chores 10 26 36
Total 59 42 101
Ans
wer
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Laptop Computer
No Laptop Computer Total
Desktop Computer
No Desktop Computer
Total
Survey your class to find out if each student has a laptop computer and/or desktop computer at home.
Make a two-way table showing your results.
Two-Way Tables
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Relative Frequency
Using two-way tables, we can calculate relative frequencies.
Relative frequencies are ratios that compares the value of a certain category to the subtotal in that category.
As you have previously learned, the frequency is the quantity of just how many of a certain event occurs.Relative frequency is how many compared to the subtotal. The relative frequency is written as a fraction or decimal.
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Relative Frequency
Example: There are 12 girls in a class of 20 students.
The frequency of number of girls in a class is 12.The relative frequency of the number of girls in the class is or 0.60.
What is the frequency of girls in your class? What is the relative frequency?
What is the frequency of boys in your class? What is the relative frequency?
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School 5 7 12
Do Not Take the Bus
to School6 12 18
Total 11 19 30
Relative Frequency
Calculate the relative frequency for the two-way table from earlier by row and then by column.
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
0.42 + 0.58 = 1.00
Do Not Take the Bus
to School
0.33 + 0.67 = 1.00
Total0.37 + 0.63 = 1.00
For this cell, the relative frequency of students taking a bicycle to school or the bus to school is divided by the total number of students that take the bus to school.
Relative Frequency
By row:
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
Do Not Take the Bus
to School
Total 1.00 1.00 1.00
For relative frequency by column, the number of students that take a bicycle to school or take a bus to school is divided by the number of students that take a bicycle to school.
Relative Frequency
By column:
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
0.42 + 0.58 = 1.00
Do Not Take the Bus
to School
0.33 + 0.67 = 1.00
Total0.37 + 0.63 = 1.00
Let's answer some questions using the relative frequencies.
By row:
What is the relative frequency of students that take a bicycle to school and also take a bus to all students taking a bus to school?
Relative Frequency
Ans
wer
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
0.42 + 0.58 = 1.00
Do Not Take the Bus
to School
0.33 + 0.67 = 1.00
Total0.37 + 0.63 = 1.00
By row:
What is the relative frequency of students that do not take a bicycle to school and do not take a bus to all students that do not take a bus to school?
Relative FrequencyA
nsw
er
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
0.42 + 0.58 = 1.00
Do Not Take the Bus
to School
0.33 + 0.67 = 1.00
Total0.37 + 0.63 = 1.00
By row:
37 What is the relative frequency of students that take a bicycle to school but do not take a bus to the total number of students that do not take the bus?
Ans
wer
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Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
0.42 + 0.58 = 1.00
Do Not Take the Bus
to School
0.33 + 0.67 = 1.00
Total0.37 + 0.63 = 1.00
By row:
38 What is the relative frequency of the students that do not take a bicycle to school, but do take the bus to the all the students that take the bus to school?
Ans
wer
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39 By Column:What is the relative frequency of students that take a bicycle to school and also take a bus to school, to the total number of students that take a bicycle to school?
By column: Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
Do Not Take the Bus
to School
Total 1.00 1.00 1.00
Ans
wer
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By column: Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
Do Not Take the Bus
to School
Total 1.00 1.00 1.00
40 What is the relative frequency of students that do not take a bicycle to school and do not take the school bus to the total number of students that do not take a bicycle to school?
Ans
wer
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By column: Take a Bicycle to School
Do Not Take a Bicycle to School Total
Take the Bus to School
Do Not Take the Bus
to School
Total 1.00 1.00 1.00
41 What is the relative frequency of students that take a bicycle to school, but do not take the bus to all students that take a bicycle to school?
Ans
wer
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Allowance No Allowance Total
Chores 49 16 65No Chores 10 26 36
Total 59 42 101
Use the following two-way table to calculate the relative frequencies by row.
Relative Frequency By Row
Allowance No Allowance Total
Chores
No Chores
Total
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Allowance No Allowance Total
Chores 1.00
No Chores 1.00
Total 1.00
For example, does there seem to be a relationship between whether or not a student receives an allowance compared to whether or not a student does chores?
By row:
Why do we calculate relative frequencies? We can use relative frequencies to determine if there is an association between the two categories.
Relative Frequency
Approximately 0.75 or 75% of students that receive an allowance do chores, and out of those that do chores only 0.25 or 25% of students receive no allowance.
Slide 99 / 122
Allowance No Allowance Total
Chores 49 16 65No Chores 10 26 36
Total 59 42 101
Use the following two-way table to calculate the relative frequencies by column.
Relative Frequency By Column
Allowance No Allowance Total
Chores
No Chores
Total
Is there a relationship between students that do chores to the amount of students that receive an allowance?
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Cat No Cat TotalDog
No DogTotal
Construct a two-way table using the following information.
Kelly found that 49 people had dogs in her school. Out of the 49 people, 30 people had cats. 50 people had cats in her school.22 people had neither cats nor dogs at home.
Two-way Table
Slide 101 / 122
Cat No Cat TotalDog
No DogTotal
Cat No Cat TotalDog
No DogTotal
By row:
By column:
Relative Frequency
Using the two-way table, calculate the relative frequencies by column and by row.
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Cat No Cat TotalDog
No DogTotal
42 What is the relative frequency of the people who have a cat and a dog at home to the number of people that have cats?
Cat No Cat Total
Dog 30 19 49
No Dog 20 22 42
Total 50 41 91
Ans
wer
Slide 103 / 122
Cat No Cat TotalDog
No DogTotal
43 What is the relative frequency of the people who have a dog and a cat to the number of people that have a dog?
Ans
wer
Slide 104 / 122
Cat No Cat TotalDog
No DogTotal
44 What is the relative frequency of the people who have no cat, but have a dog to the number of people that have no cats?
Ans
wer
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45 The table shows the results of a random survey of students in grade 7 and grade 8. Every student surveyed gave a response. Each student was asked if he or she exercised less than 5 hours last week or 5 or more hours last week. Based on the results of the survey, which statements are true? Select each correct statement.
A More grade 8 students were surveyed than grade 7 students.
B A total of 221 students were surveyed.
C Less than 50% of the grade 8 students surveyed exercised 5 or more hours last week.
D More than 50% of the students surveyed exercised less than 5 hours last week.
E A total of 107 grade 7 students were surveyed.
From PARCC EOY sample test calculator #3
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Survey your classmates to find out if they play sports and/or play an instrument. Construct a two-way table displaying the results. (Write "yes" or "no") Then calculate the relative frequencies by row and by column.
Is there a relationship between the number of students that play sports vs. the number of students that play an instrument?
Construct a Two-way Table
Slide 107 / 122
Glossary
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Slide 108 / 122
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Instruction
Bivariate DataTwo sets of related data that is being
compared. Data of two variables.(Two-Variable Data)
Variables:1. Temperature 2. Sales
Variables:1. Shoe Size
Variables:1. Hours 2. Math Grade
Bivariate Data
1 variable
Univariate Data
Slide 109 / 122
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(53,180)
(77,610)
range =
610 - 180
If it is 50o outside, what would
be the predicted ice cream sales? y = 17x - 721 y = 17(50) - 721 y = 851 - 721 y = 129
$129
$129 < $180
If it is 90o outside, what would
be the predicted ice cream sales?
y = 17x - 721 y = 17(90) - 721 y = 1,530 - 721 y = 809
$809
$809 > $610
Extrapolation
A data point that is outside the range of data.
Slide 110 / 122
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FrequencyThe quantity of just how many of a
certain even occurs.
The frequency of
kids who do not take
the bus to
school is 18.
The frequency of
kids who take the
bus to school is 12.
The frequency of
kids who ride their
bikes to school is 11.
Slide 111 / 122
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If it is 70o outside, what would
be the predicted ice cream sales?
y = 17x - 721 y = 17(70) - 721 y = 1,190 - 721 y = 469
$469
$180 < $469 < $610
If it is 63o outside, what would
be the predicted ice cream sales?
$350
$180 < $350 < $610
y = 17x - 721 y = 17(63) - 721 y = 1,071 - 721 y = 350
Interpolation
A data point that is inside the range of data.
(53,180)
(77,610)
range =
$610 -
$180
Slide 112 / 122
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Linear
A graph that is represented by a straight line.
Slide 113 / 122
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Line of Best FitA line on a graph showing the general
direction that a group of points seem to be heading. Trend Line.
Slide 114 / 122
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Negative Association
A correlation of points that is linear with a negative slope.
Slide 115 / 122
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No Association
A correlation of points that is linear with a slope of zero. A horizontal line graph.
Slide 116 / 122
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Non-Linear
A graph that is not represented by a straight line. A curved line.
Slide 117 / 122
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Positive Association
A correlation of points that is linear with a positive slope.
Slide 118 / 122
y = mx+b
y = 17x - 721 (53,180)
(73,520)
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Instruction
Prediction Equation
Temperature degrees F
Ice
Cre
am S
ales
$
If it is 70o outside, what would
be the predicted ice cream sales?
y = 17x - 721 y = 17(70) - 721 y = 1,190 - 721 y = 469
$469
An equation that is created using the line of best fit. A line that can predict
outcomes using the given data.
Slide 119 / 122
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Relative Frequency
The relative frequency of
students who only take the bus to
the total bus riders is
0.58.
The relative frequency of
students who only ride their bikes to
the total bike riders is 0.33.
The relative frequency of
students who only ride their bikes to the total students
is 0.37.
Ratios that compares the value of a certain category to the subtotal in that category.
Slide 120 / 122
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A graph of plotted points that show the relationship between two sets of data.
Scatter Plot
Slide 121 / 122
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Two-Way Table
A table that displays information as it pertains to two different categories.
School Bus vs. Bicycle
Allowance vs. Chores
Slide 122 / 122