Create a C++ program which establishes an interface that allows the user to enter in a positive floating point value. Your interface should allow the user to press a button, and the associated letter grade should appear for the user. We will use the standard grading scale for Roanoke College:
| Letter Grade | Lowest Grade | Highest Grade | 
|---|---|---|
| A | 90 | |
| B | 80 | 89 | 
| C | 70 | 79 | 
| D | 60 | 69 | 
| F | 59 | 
 
Please submit your completed project to inquire by the beginning of class on Monday, Feb. 13th