Question 1) 10 Marks

The manager at Royal Tire made some changes (treatment) in an effort to reduce the amount of time it takes to rotate tires. Although the manager expects this job to take 20 minutes, he wants to know if the treatment was successful. A study of 100 customers showed a mean of 15 minutes with a standard deviation of 5 minutes. If you were to advise the manager, what would you say?

Question 2) 10 Marks

The commissioner for the region of Yazoo in Alberta, thinks that his region has fewer car accidents than the region of York in Ontario. A sample of 64 days in Yazoo, showed a mean number of accidents of 360. On the other hand, a similar sample of 100 days in York revealed a mean number of accidents of 350. The population standard deviation for Yazoo is 16 accidents and for York is 25 accidents. If you were to advise the commissioners, what would you tell them?

Question 3

In a retail store three different product shelf displays were used to see if there was any change in the volume of sales. The sales in $ for each product display is shown below. Assume a 0.05 level of significance.

Display 2 3 58 58 48 64 69 57 55 71 59 66 64 47 67 49 68