High School

In a keyboarding class, the instructor guarantees that at the end of the course, the class will type an average of 40 words per minute. The table shows the words per minute typed for a random sample of 10 students for their final exam.

Based on these data, did the students type more or less than the instructor predicted, and by how much?

A. The students typed less than predicted by 1.2 words per minute.
B. The students typed less than predicted by 38.8 words per minute.
C. The students typed more than predicted by 1.2 words per minute.
D. The students typed more than predicted by 38.8 words per minute.

Answer :

Based on the data, the correct option is B. The students typed less than predicted by 38.8 words per minute.

How do we find whether the students typed more or less than the instructor predicted?

To determine whether the students typed more or less than the instructor predicted, we will calculate the average words per minute typed by the students in the sample.

To find the average, we shall sum up the words per minute typed by each student and divide by the number of students (10):

Average = (35 + 44 + 38 + 27 + 65 + 40 + 31 + 53 + 25 + 30) / 10

Average = 388/10

Average = 38.8 words per minute.

Hence, the students typed, on average, 38.8 words per minute, which is less than the instructor's guarantee of 40 words per minute.

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