Problem
Write a function that computes the average and standard deviation of four scores. The standard deviation is defined to be the square root of the average of the four values: (si - a) 2, where a is the average of the four scores s1, s2, s3, and s4. The function will have six parameters and will call two other functions. Embed the function in a program that allows you to test the function again and again until you tell the program you are finished.