mr. chen period #3 2012-2013 by: erick ojeda eduardo rangel miguel organista mustafa sann
TRANSCRIPT
Do you like Starbucks?
MR. ChenPeriod #3 2012-2013
By: Erick OjedaEduardo RangelMiguel Organista
Mustafa Sann
California Standards•8.0 Student organized and describe distribution
of data by using of different methods, including frequency table, histogram, standard line and bar graphs, stem-and-leaf displays, scatter plots, and box of whisker plots.
•17.0 Students determine confidence interval for a simple random sample from a normal distribution of data and determine the sample size required for a desired margin of error.
•18.0 Student determine the P-value for a statistic for a simple random sample from a normal distribution
Hypothesis
We believe that the average amount of students, juniors and
seniors, who like Starbucks is less than 64%.
Data collection
We will collect data by using stratified sample method. We ask juniors and seniors at Century whether or not they like Starbucks, to survey 100 students (50 juniors and seniors.)
Data Number of Seniors who answered Yes.
35 Number of Seniors who answered No.
15 .Number of Juniors who answered Yes.
29 .Number of juniors who answered NO
21
Statistics
From our Survey we asked Fifty Seniors and Fifty Juniors, Mean is .54592 standard deviation is .73408.
Confidence interval 95% confidential interval 1z-interval (. 54592, .73408) We are 95% confident the mean of
students that like starbucks are between .546 to .734
Hypothesis Testing Hypothesis
Test Statistics
At 5% level of significance, we failed to reject . There is not enough evidence to support the claim.
)(64.:
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Error Analysis Our sample proportion is 54.6%, and
the 95% confidence level for the population proportion is between 49.6% to 59.6%.
Our sample error is due to possible underrepresentation of the of the population. We might need to take more samples due to false responses, people unwilling to answer our question, and student absences.
Conclusion We hypothesized that the amount of Century
students who prefer Starbucks is less than 64%. In our survey of 100 students, (50 juniors and 50 seniors), we found the sample proportion of .54592 with the standard deviation of .73408. We conclude that the population proportion for all the students is between 49.6% and 59.6% with 95% confidence. We tested our initial hypothesis with 5% level of significance, and confirm out hypothesis is incorrect.