in the advertisements for a large university, the dean of the School of Business claims that the average salary of the school's graduates one year after graduation is $800 per week, with a standard deviation of $100. A second-year student in the business school who has just completed his statistics course would like to check whether the claim about the mean is correct. He does a survey of 25 people who graduated one year earlier and determines their weekly salary. He discovers the sample mean to be $750. Test the null hypothesis that the dean's claim is correct (mu = 800) against the alternative hypothesis that is smaller than 800 (mu < 800). Compute the statistic and the p-value, and draw your conclusion.