Question

A student calculated the mean of a set of 15 numbers and gets a result of 41.6. In calculating the mean, he inadvertently entered 117 for one of the numbers into his calculator instead of 17. What is the true mean of the data

Answer 1

35.93

Explanation:

If the mean of 15 numbers is 41.6, the sum of these numbers must be (15)*(41.6) = 624

We n=know one of these numbers is the 117 that was entered by mistake. Subtract that out and replace it with the correct number, 17. In essence we are modifying the number by (-117+17) or -100.

524 is the corrected value. Divide that by 15 to find the ciorrect mean:

(524)/15 = 34.93