Question

Identify any outliers of the data set. Then determine the effect that the outlier has on the mean.

375, 350, 400, 375, 375, 425, 350, 125, 400
a)425; increases the mean
b)125; decreases the mean
c)425; decreases the mean
d)125; increases the mean

Answer 1

c)425; decreases the mean. There are two outliers in the data set, 125 and 425. The outlier 425 decreases the mean.

Step-by-step explanation:

There are two outliers in the data set: 125 and 425. To determine the effect of an outlier on the mean, we need to calculate the mean with and without the outlier. Without the outliers, the mean is (375+350+400+375+375+350+400)/7 = 375. With the outlier 425 included, the mean is (375+350+400+375+375+425+350+125+400)/9 = 358.33. Therefore, the outlier 425 decreases the mean.

Outliers: 125, 425

Effect on Mean: Decreases the mean