Textbooks are getting more expensive for undergraduate students. Your local community college
wants to take an SRS of undergraduate students to find out how much money they spend on textbooks. The college
wants to construct a 90% confidence interval with a margin of error of less than $5. Based on last year's data, they
estimate the population standard deviation to be $45. What are the minimum number of students the college needs
to sample in order to have this margin of error?