Question

the mean of a 6 number dataset is 20 if one of the numbers is 15 and you remove it from a dataset what us the mean of the remaining 5 numbers in the data?

Answer 1

21

Explanation:

If the mean of the data set is 20, we know that it is the sum of all the values in the data set, divided by the number of values. So, with s representing the sum, the mean is s/6 = 20

To undo division, multiply 20 by 6. 20*6 = 120.

120 is the sum of all of the values. Since we're taking out the number 15, subtract it from 120. You're left with 105, which is the sum of the rest of the numbers. Since you now only have 5 numbers, divide 105 by 5 and you get the new mean, which is 21.