Question

Find the standard deviation for the given data. Round your answer to one more decimal place than the original data.
10)

{15, 13, 31, 42, 58, 78}

A)

36.5

B)

534.3

C)

39.5

D)

23.1

Answer 1

Well, it certainly isn't B; that is much too large. And it isn't C, because 39.5 is the mean. That leaves A) or D).

Are you familiar with the definition of standard deviation? You should go ahead and calculate it. It isn't that hard.

The individual deviations from the mean are: -24.5, -26.5, -8.5, 2.5, 18.5 and 38.5.

Next take the average of the SQUARES of those numbers: 534.3

The standard deviation is the square root of that number. (It is sometimes called the "root mean square")