A researcher computed the mean, median and standard deviation for a set of performance score. If 5 were to be added to each score, which of these three statistics would change?

First of all, we should understand what each term means. Then the answer would be very

straight-forward. Mean: The average of all values. Median: The value in the center. Standard deviation: Variance is the square root of variance. Variance is the average of the

square of the difference between each value and the mean. Since you add 5 to each value, definitely the average would be n1+5 + n2+5 + n3+5 +... / n ..

where n is the number of values. new mean = (n1+n2+n3+... + 5n) / n

= (n1+n2+ .. ) / n + 5

= old mean + 5 Thus the mean changes by 5. The median is either the middle value in the set (if the number of value