3.10 After introducing a new teaching curriculum, a principal would like to determine whether the grade distribution in her school is significantly different than it has been in previous years. Suppose that Table 3.4 represents the distribution over previous years.

Further, suppose that in a random sample of 100 students, 25 received an A, 30 received a B, 30 received a C, 14 received a D, and 1 received an F.

a. Use the Pearson chi-squared test to determine whether there is sufficient evidence to conclude that this grade distribution is significantly different than it had been in previous years.

b. Using the results from part (a), which grades contribute the least and greatest amounts to the overall chi-squared test statistic? How can this be interpreted?