2. People tend to be more generous after receiving good news. Does their generosity change after receiving bad news? The average tip left by adult Americans is 16.5%. 25 patrons of a restaurant were randomly selected to be given a message on their bill warning them that the following day's weather would be bad. Their tip percentages were recorded. The mean tip as a percentage of the total bill was 15.62 with a standard deviation of 2. Is there enough evidence that the mean tip percentage for all patrons of this restaurant changed from 16.5% when they receive a message warning them that tomorrow's weather will be bad? Assume tipping percentage is normally distributed in the population. Use a t-critical of 2.06. [8 pts) a. Write the null and alternate hypothesis for this test. b. Calculate the test statistic for this test. Show all your work. c. Write a complete answer detailing the results, including any necessary statistics