Terry Downes owns a commercial cleaning company.

He has conducted a survey of customers to determine how satisfied they are with the work performed. He devised a rating scale between 0 and 100, with 0 being poor and 100 being excellent service. He selected a random sample of 14 customers and asked them to rate the service. He also recorded the number of worker hours spent in the customer’s facility. These are in the file named Downes.

a. (1) Draw a scatter plot showing these two variables, with the y variable on the vertical axis and the x variable on the horizontal axis. (2) Describe the relationship between these two variables.

b. (1) Develop a linear regression model to explain the variation in the service rating. (2) Write a short report describing the model and showing the results of pertinent hypothesis tests, using a significance level of 0.10.