Question

A set 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?

Answer 1

Answer: 240.127659574469 which is approximate. Round this however you need to.

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Explanation:

Let,
A = sum of the 94 non-outlier values
B = sum of the 6 outliers

The 100 data values has a mean of 267, so 
(A+B)/100 = 267
A+B = 267*100
A+B = 26700
A = 26700-B

The mean of the six outliers is 688, so
B/6 = 688
B = 688*6
B = 4128

Which means,
A = 26700-B
A = 26700-4128
A = 22572

and the mean of the 94 non-outliers is
A/94 = 22572/94 = 240.127659574469 which is approximate. Round this however you need to.