The fivenumber summary below shows the grade distribution of

The five-number summary below shows the grade distribution of two STAT 200 quizzes for a sample of 500 students.

For each question, give your answer as one of the following: (a) Quiz 1; (b) Quiz 2; (c) Both quizzes have the same value requested; (d) It is impossible to tell using only the given information. Then explain your answer in each case. (4 pts each)

Which quiz has less interquartile range in grade distribution?

Which quiz has the greater percentage of students with grades 90 and over?

Which quiz has a greater percentage of students with grades less than 60?

Solution

IQR = 40 for Quiz I and 55 for Quiz II

Hence quiz I has less interquartile range in grade distribution

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Quiz 2 has the greater percentage of students of grades 90 and over

Quiz I has the less percentage of students of grades <60