The college bookstore tells prospective students that theaverage cost of its textbooks is $108 with a standard deviation of$4.50. A group of smart statistics students thinks that the averagecost is higher. In order to test the bookstore’s claim againsttheir alternative, the students will select a random sample of size100. Assume that the mean from their random sample is $112.80.
- Perform a hypothesis test (using R) at the 5% level ofsignificance and state your decision. Also construct a 90%confidence interval (using R) for the average cost oftextbook.
- Perform the above task under the assumption that the studentsselected a random sample of size 10.
- Write the difference between your findings of (1) and (2).
