✓#1. Design, create, and test a C program to determine the letter grade associated with a

numerical grade. The user will enter a numerical grade (double) and the program will then

display the letter grade corresponding to the numerical grade. For example, if user enters 72,

then program displays "C". Use grade policy: F <60; 60>= D <70; 70<=C<80; 80<-B<90;

90<=A< 100. Include sample output with program. Pick good test cases. Individual

assignment.