1. In the Excel file Cell Phone Survey, test the hypothesis that the mean responses for Value for the Dollar and Customer Service do not differ by gender. 2. For the data in the Excel file Graduate School Survey, perform a test for proportions at level 10% to determine whether the proportion of individuals who plan to attend graduate school is the same for married and unmarried groups. 3. A study of nonfatal occupational injuries in the United States found that about 31% of all injuries in the service sector involved the back. The National Institute for Occupational Safety and Health (NIOSH) recommended conducting a comprehensive ergonomics assessment of jobs and workstations. In response to this information, Mark developed a unique ergonomic handcart to help field service engineers be more productive and also to reduce back injuries from lifting parts and equipment during service calls. Using a sample of 382 field service engineers who were provided with these carts, Mark collected the following data: a. Determine if there is statistical evidence that average call time has decreased as a result of using the cart. What other factors might account for any changes? b. Determine if there is statistical evidence that the proportion of back injuries has decreased as a result of using the cart.