Question

Desmond's Surf Shop had the following number of customers on each of the last ten days:

160, 175, 166, 180, 172, 178, 174, 170, 178, 300

As much as Desmond would like to think having 300 customers in one day is normal, he knows that it does not reflect the number of customers that come to the shop each day.

When he removes the outlier of 300 from the data, which of the following happens?

Hint:

Find the mean with the original data. (Get the sum and divide by the number of data points.)
Then find the mean of the data points once the 300 is removed.
Find the mode.
1Points
Select TWO that apply.

A
The mode does not change.

B
The mean does not change.

C
The mean drops from 185.3 to 172.6.

Answer 1

A The mode does not change.

C The mean drops from 185.3 to 172.6.

Explanation:

Mean of original data

Mean = (160 + 175 + 166 + 180 + 172 + 178 + 174 + 170 + 178 + 300)/10 = 1853/10 = 185.3

Mean with outlier removed

Mean = (1853 - 300)/9 = 1553/9 = 172.6

The mean drops from 185.3 to 172.6 when the outlier is removed.

Mode

The mode of a data set is the value that occurs most often.

Mode = 178

The mode does not change when you remove the outlier.