題組內容

3. (10%) The average starting salary of students who graduated from colleges of Business in 2018 was $38,400. A sample of 100 graduates of 2019 showed an average starting salary of $40,000. Assume the standard deviation of the population is known to be $8000. We want to determine whether or not there has been a significant increase in the starting salaries.


a. State the null and alternative hypotheses. Test the hypothesis at the \( 5\% \) level of significance. What do you conclude?