Objective: write a program that converts a numeric grade into a letter grade.

What to do?

• Write a C program converter that prompts the user to enter an integer:

Please enter a numeric grade: 

• converter interprets the entered value as a numeric grade on a 0-100 point scale and converts it into a letter grade as follows:
  • [100..90] is an A;
  • (90..80] is a B;
  • (80..70] is a C;
  • (70..60] is a D;
  • (60..0] is an F;
  • all other values are invalid.
• converter will print out valid results that should look like this:

Please enter an numeric grade: 75 Your grade is a C. 

• converter will produce an error message in response to invalid entries:

Please enter an numeric grade: 190 You entered an invalid value. 

Please enter an numeric grade: abc Your input could not be interpreted as an integer value.