Average of Grades Write a program with a 'while' loop that asks the user to enter a series of test grades in the range 0 to 100. The user should enter a negative number to signal the end of grade input. After all the grades have been entered, the program should display the average of the grades. The average should be displayed to one decimal place. Sample execution: Python 3.43 Shell File Edit Shell Debug Options Window Help Python 3.4.3 (v3 .4.3:9b73f1c3e601, Feb 24 2015, 22:44:40) [MSC v.1600 64 bit (AM D64) on win32 Type "copyright", "credits" or "license 0" for more information RESTART Enter a test score,-1 to get the average: 97 Enter a test score, -1 to get the average: 96 Enter a test score, -1 to get the average: 88 Enter a test score,-1 to get the average: 74 Enter a test score, -1 to get the average: -1 The average for all the grades is: 88.8 Ln:11 Col:4