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 survey indicates that 53 percent of registered have a favorable opinion of a certain politician. One year later, another sample of 230 registered voters in the same area indicates that 102 have a favorable opinion. Does the second sample indicate a significant shift in the proportion having a favorable opinion?
Problem 2
Data from a credit card company indicates that in a certain market, families dined out an average of 2.1 nights per week with a standard deviation of 0.8 in 2001, and 2.0 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 retailer compares same-store sales in the months immediately before and after an ad campaign at 120 stores and finds an average increase of $3.1 (measured in thousands of dollars per week), with a standard deviation of 12.1. Does this study support the claim that the ad campaign significantly increased sales?