Question

The data to represent average test scores for a class of 24 students includes an outlier value of 89. If the mean, including the outlier of 89, equals 77, which statement is always true about the new data when the outlier is removed?

The mean would increase.
The mean would decrease.
The median would increase.
The median would decrease.

Answer 1

The mean would decrease.

Explanation:

i took the test

Answer 2

The mean would decrease.

Explanation:

If the mean score of 24 students is 77.

The total score of 24 students = 24 x 77 = 1848

If the outlier is removed, the mean would become

New total score / number of students = (1848 - 89) / (24 - 1)

1759/23 = 76.5

It can be seen that the mean decreased.