week 9 homework assignment 8

§  Homework Assignment 8

Due in Week 9 and worth 30 points

Suppose the number of equipment sales and service contracts that a store sold during the last six (6) months for treadmills and exercise bikes was as follows:

                               Treadmill           Exercise Bike

Total sold                        185                             123

Service contracts             67                               55

The store can only sell a service contract on a new piece of equipment. Of the 185 treadmills sold, 67 included a service contract and 118 did not.

Complete the following questions in the space provided below:

1.     Construct a 95 percent confidence interval for the difference between the proportions of service contracts sold on treadmills versus exercise bikes.

2.     Is there a major difference between the two pieces of equipment? Why or why not?