Aset of data with 100 observations has a mean of 267. there are six outliers in the data set, which have a mean of 688. if the six outliers are removed, what is the mean of the new data set?
a. 251.0
b. 311.6
c. 240.1
d. 284.0

We know the mean is the sum divided by the total number. So to find the new mean we need to subtract the sum of the outliers from the sum of all 100. The mean of the 100 is 267, so to find the sum you multiple 267 by 100 = 26700 then find the sum of the 6 outliers. The mean of the outliers is 688, and 688 x 6 = 4128. Now we know what we need to get rid of the outliers
26700 - 4128 = 22572. Now we have the sum of the point without 6 outliers and we need to divide it by the total number of data point to find the mean.
22572/(100-6)= 240.1
we did 100-6 because of the 6 outliers removed from the set of 100.
so the mean without the outliers is 240.1

It would be the second one because it passes the vertical line test