a. A software development company claims that its new project management software has reduced the average time required to complete projects. According to past data, the population standard deviation for project completion time is known to be 15 days. The company wants to test this claim using a 5% significance level. They collect a sample of 64 completed projects and find a sample mean completion time of 82 days. Is there enough evidence to support the company's claim that the new software has reduced the average project completion time?