3. Twenty graduate students in business were asked how many credit hours they were taking in the current quarter. Their responses are shown as follows ( 2p3[) : a. Determine the mean, median, and mode for this sample of data. Write a sentence explaining what each means. b. It has been suggested that graduate students in business take fewer credits per quarter than the typical graduate student at this university. The mean for all graduate students is 9.1 credit hours per quarter, and the data are normally distributed. Set up the appropriate null and alternative hypotheses, and determine whether the null hypothesis can be rejected at a 95 percent confidence level