One of the major measures of the quality of service provided by any organization is the speed with which it responds to customer complaints. A large family-held department store selling furniture and flooring had undergone a major expansion in the past several years. In particular, the flooring department had expanded from 2 installation crews to an installation supervisor, a measure, and 15 installation crews. The store had the business objective of improving its response to complaints. The variable of interest was defined as the number of days between when a complaint was made and when it was resolved. Prior to increasing the staff, the mean number of days to resolve a complaint was 45. Data were collected from 50 complaints that were made in the past year. The sample data showed the mean number of days for resolution was 40 with a standard deviation of 18 days. Perform the appropriate test to determine if the mean number of days it takes to resolve a complaint decreased after the staffs was increased. Use alpha = .05.............b. In addition to reducing the time it takes to resolve a complaint, the store also wanted to decrease the percent of flooring jobs that resulted in a customer complaint. Before expanding the crew, the percentage of flooring jobs resulting in a customer complaint was 8%. In a sample of 225 flooring jobs, 15 resulted in a customer complaint. Is there evidence the percentage of jobs with customer complaints decreased as well? Perform the test at alpha = .05

And what is the decision rule for each part?