Question

Joey's first 14 quiz grades in a marking period were as follows: Suppose Joey has an unexcused absence for the 15th quiz, and he receives a score of 0. What is the new mean of Joey's quiz grades? What property of the mean does this illustrate?

Answer 1

To find the new mean of Joey's quiz grades, we calculate the sum of his first 14 quiz grades and add the score of 0 for the 15th quiz. Then we divide the total sum by 15 to find the new mean. This illustrates the property of the mean where a value significantly different from the rest can greatly affect the average.

Step-by-step explanation:

To find the new mean of Joey's quiz grades, we need to calculate the sum of his first 14 quiz grades. Then we add the score of 0 for the 15th quiz and divide the total sum by 15. This will give us the new mean. Let's do the calculations:

Quiz grades: 75, 80, 85, 90, 70, 80, 95, 85, 90, 80, 85, 75, 90, 95

Total sum = 75 + 80 + 85 + 90 + 70 + 80 + 95 + 85 + 90 + 80 + 85 + 75 + 90 + 95 = 1200

New mean = 1200/15 = 80

This illustrates the property of the mean where a value significantly different from the rest can greatly affect the average. In this case, Joey's absence and score of 0 had a noticeable impact on his overall mean.