The Bowkes Company collected information on the retail prices of books. In 2005, the mean retail price of all history books was $ 78.01. This year's retail prices for 40 randomly selected history books has a mean of $ 81. 44 and standard deviation of 7.61. At the 1% significance level, do the data provide sufficient evidence to conclude that this year's mean retail price of all history books has increased from 2005 mean of $ 78.01?

Compute the value of the test statistic. Find the critical value(s).