Here are 10 test scores: 30, 74, 76, 77, 78, 79, 80, 80, 82, 84. The mean of these scores is 74.

Does this set have an outlier and, if so, how does removing it affect the mean?

A.
The set has 30 as an outlier and removing it decreases the mean by about 10.

B.
This data set has no outliers.

C.
The set has 30 as an outlier and removing it decreases the mean by about 5.

D.
The set has 30 as an outlier and removing it increases the mean by about 5.

@autumnroseT

Question

Here are 10 test scores: 30, 74, 76, 77, 78, 79, 80, 80, 82, 84. The mean of these scores is 74. 
 
Does this set have an outlier and, if so, how does removing it affect the mean?
 
 A.
The set has 30 as an outlier and removing it decreases the mean by about 10.
 
 B.
This data set has no outliers.
 
 C.
The set has 30 as an outlier and removing it decreases the mean by about 5.
 
 D.
The set has 30 as an outlier and removing it increases the mean by about 5.


@autumnroseT

anonymous · Answer

well 30 is definitely the outlier, so its not B. the way to solve this is to add all the numbers together (without adding 30) and then dividing the answer by 9

foxythepirate0984 · Answer

A ?

anonymous · Answer

this new mean would be 78.8 so no not A

anonymous · Answer

because instead of dividing it by 10 when we were adding 30, we'll be dividing by only 9 so the answer will be greater

foxythepirate0984 · Answer

D

anonymous · Answer

yes :)