WARM – UP #51. Graph 4x – 5y = -20
What is the x-intercept?
What is the y-intercept?
2. Graph y = -3x + 2
3. Graph x = -4
WARM – UP #5 SOLUTIONS1. Graph 4x – 5y = -20
x-intercept (y = 0) 4x - 5(0) = -20
4x = -20 x = -5
(-5, 0)
y-intercept (x = 0)
4(0) - 5y = -20
-5y = -20
y = 4
(0, 4)
WARM – UP #5 SOLUTIONS2. Graph y = -3x + 2
Slope = -3
y-int: (0, 2)
WARM – UP #5 SOLUTIONS4. Graph x = -4
LESSON 2-5 USING LINEAR MODELS
Algebra II
LEARNING OBJECTIVE
To write linear equations that model real-world data
To make predictions from linear models
Scatter Plot – graph that relates two sets of data by plotting the data as ordered pairs
Correlation – strength of the relationship between data sets
Correlation Coefficient r – indicates strength of correlation
Positive Correlationr is closer to 1
Negative Correlationr is closer to -1
No Correlation r is closer to 0
Line of Best Fit – the trend line that gives the most accurate model of related data
To write the equation of the line:
-Find slope of the line
-Use the slope and a point to write an equation of the line
1. a. Make a scatter plot
b. Sketch a line of best fit
c. What is the correlation?
d. What is the equation for the line of best fit?
A. SCATTER PLOT
B. LINE OF BEST FIT
C. STRONG NEGATIVE CORRELATION!
D. LINE OF BEST FITUse 2 points (0, 100) & (3, 75)
y = -8.3x + 100
2. Using #1’s linear model, predict what your test score will be if you spend 10 hours on the computer daily.
y = -8.3x + 100
y = -8.3(10) + 100
y = -83 + 100
y = 17
17%!! Spend more time studying and less time on the computer!!
TICKET OUT THE DOOR The table shows population and licensed driver from a recent year.
a. Make a
scatter plot
b. Sketch a
line of best
fit
c. Is the correlation strong or weak? Explain.
ASSIGNMENT:
PG. 96 # 7 – 11, 14 - 17, 27 - 29
Don’t Cry. You
got this!!!
