The prices of used books at a large college bookstore are normally distributed. If a sample of 23 used books from this store has a mean price of...

The prices of used books at a large college bookstore are normally distributed. If a sample of 23 used books from this store has a mean price of $27.50 with a standard deviation of $6.75, use Table 10.1 in your textbook to calculate the following for a 95% confidence level about the population mean. Be sure to show your work.

a. Degrees of freedom

b. The critical value of t

c. The margin of error

d. The confidence interval for a 95% confidence level