MA207 Final Exam - Takehome Portion
For each of the problems below, use the technology guide to perform a statistical analysis.
You should justify your choice of method, including any assumptions made in the use of the method.
You should indicate whether a two-tailed, left-tailed, or right-tailed analysis is appropriate,
and, in hypothesis testing problems, state the null and alternative hypotheses.
If the problem does not specify a level of significance, you should choose one.
Problem 1
A retailer compares same-store sales in the months immediately before and after an ad campaign at 72 stores and finds an average increase of $8.1 (measured in thousands of dollars per week), with a standard deviation of 10.1. Does this study support the claim that the ad campaign significantly increased sales?
Problem 2
Data from a credit card company indicates that in a certain market, families dined out an average of 2.3 nights per week with a standard deviation of 0.8 in 2001, and 1.9 nights per week with a standard deviation of 0.7 in 2005. Does this data indicate a significant drop in the frequency of dining out in this market?
Problem 3
A survey of 150 randomly selected registered voters indicates that 68 have a favorable opinion of a certain politician. One year later, another sample of 130 registered voters in the same area indicates that 52 have a favorable opinion. Is there a significant difference between the two samples?