MA145 Final Exam - Takehome Portion
For each of the problems below, use the MA145 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 television network claims that a show in a certain time slot has a 23 percent share of the
viewing audience and sets advertising rates accordingly. An advertiser running a commercial during the show wants to verify that the market share is 23 percent, so a telephone survey is taken during the show. The survey calls 500 randomly selected households and finds
that 102 are tuned in to the show. Does this data support the network's audience share estimate, or should the advertiser negotiate a refund?
Problem 2
A package delivery service purchases trucks that get 15 miles per gallon in city driving according to the manufacturer. A sample of 33 trucks are tested and the average mileage is 12.1 miles per gallon with a sample standard deviation of 2.1. Does this data support the claim
that the actual mileage is less than 15?
Problem 3
A retailer has 54 stores. If the average change in same store sales from 2004 to 2005 is $3,100 per week with a standard deviation of 1211, does this represent a significant change?