many hours per week they spend on the phone. The sample mean was 4.75 hours with a sample standard deviation of 2.0. Conduct a hypothesis test. The null and alternative hypotheses are as follows: a. Ho: x=4.5, H:X>4.5 b. H: H 4.5, H H 4.75 d. Ho: = 4.5, H: H>4.5 9.2 Outcomes and the Type I and Type II Errors 66. State the Type I and Type II errors in complete sentences given the following statements. a. The mean number of years Americans work before retiring is 34.