MAT 510 WEEK 9 Homework Assignment 8

MAT 510 WEEK 9 Homework Assignment 8 
Suppose the number of equipment sales and service contracts that a store sold during the last six  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?