Write a program that asks the user to enter five test scores. The program should display a letter grade for each score and the average test score. Write the following functions in the program:

• Calc_average. This function should accept five test scores as arguments and return the average of the scores.

• Determine_grade. This function should accept a test score as an argument and return a letter grade for the score based on the following grading scale:

Score 90-100 80-89 70-79 60-69 Below 60 Letter Grade A B C D DF