Write a program that prompts the user to enter three number grades (doubles are probably best here). The program computes the average of the three grades and displays the letter grade for the three original grades and for the average. Letter grades are computed as follows (this requires if-statements):

A+:90-100 A:80-89 B:70-79 C:60-69 D:50-59 F: <50

ouput should resemble: Please enter three grades: 60 80 100 Average grade: 80 or A End of program.

or Please enter three grades: 75.5 81.3 19.7 Average grade: 58.83 or D End of program.

Since most grades are between 0 and 100 we shouldnt proceed with the program if any of the grades are outside of that range. If any of the grades are < 0 or > 100, stop the program with an appropriate message. Example: Please enter three grades: -75.5 81.3 19.7 One of the grades is out of range. End of program.