Curve Grades Statisticians use the concepts of mean and standard deviation to descri...

Curve Grades Statisticians use the concepts of mean and standard deviation to describe a collection of data. The mean is the average value of the items, and the standard deviation measures the spread or dispersal of the numbers about the mean. Formally, if x₁, x₂, x₃, ⋅ ⋅ ⋅ ,x_n, is a collection of data, then

and standard deviation =

The file Scores.txt contains exam scores. The first four lines of the file hold the numbers 59, 60, 65, and 75. Write a program to calculate the mean and standard deviation of the exam scores, assign letter grades to each exam score, ES, as follows, and then display a list of the exam scores along with their corresponding grades, as shown in Fig. 7.72.

For instance, if m were 70 and s were 12, then grades of 88 or above would receive A’s, grades between 76 and 87 would receive B’s, and so on. A process of this type is referred to as curving grades.