Write a C++ program that determines a letter grade for a student based on two test scores. For a numeric average x, the following grade scale is used:
Grade Range
A 90.0 ≤ x ≤ 100.0
B 80.0 ≤ x < 90.0
C 70.0 ≤ x < 80.0
Fail x < 70.0
For each student, the program will need to get two test scores from the user; both scores should be positive floating point numbers and can include 0.0. If the user enters a negative number, display an appropriate error message and reprompt the user. When the user enters two valid positive numbers, the pro-gram should calculate the average and display to the console the corresponding grade given in the first column of the table above.
The program should continue to process student scores until one of the fol-lowing occurs:
• Three passing grades have been computed. The program should then print the message "PASSING QUOTA MET" to the console and terminate.
• Two failing grades have been computed. The program should then print the message "FAILING QUOTA MET" to the console and terminate.