Question

Are grades higher on the second quiz? Here is a sample of grades from a large introductory statistics course. We are interested in testing whether the mean grade on the second quiz is higher than the mean grade on the first quiz. You may assume any required test assumptions have been met.

a) Complete the test if we assume that the grades from the first quiz come from a random sample of 12 students in the course and the grades on the second quiz come from a different, separate random sample of 12 students in the course. Clearly state the conclusion.

b) Now conduct the test if we assume that the grades recorded for the first quiz and the second quiz are from the same 12 students in the same order. For example, the first student got 72 on the first quiz and 78 on the second quiz.

c) Why are the results from a) and b) so different? Which is a better way to collect the data to

answer the question of whether grades are higher on the second quiz? Explain.

72 95 56878098 748577 62 91 82 First Qui:z Second Ọuiz | 78 | 96 | 72 | 89 | 80 | 95 | 86 | 87 | 82 | 75 | 88 | 86

Answer 1

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