Question

select the outlier in the data set. 1 71 77 88 90 94 96 99 if the outlier were removed from the data set, would the mean increase or decrease? increase decrease

Explanation:

Step1: Identify the outlier

The number 1 is far from other values in the set {1, 71, 77, 88, 90, 94, 96, 99}, so 1 is the outlier.

Step2: Analyze the effect on the mean

The mean of a data - set is $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$. The outlier 1 is much smaller than the other values. When it is removed, the sum of the remaining values divided by the number of remaining values will be larger. So the mean will increase.

Answer:

1. The outlier is 1.
2. increase