Discussion-Confidence Interval

Suppose a sporting goods store sold treadmills, exercise bikes, and equipment service contracts over the past six months as shown in the table below.

Equipment and Service Contract Sales
  Treadmill Exercise Bike
Equipment Sales 185 123
Service Contract Sales 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.

Respond to the following in a Word document and submit:

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

2. Determine if there is or is not a major difference between the two pieces of equipment and provide a rationale for your response.