Write a program that calculates the average of three test scores. The program should contain three value-returning functions: main, getTestScore, and calcAverage. The main function should call the get TestScore function to get, validate the score to make sure the value is between 0 and 100, and return each of the three test score. The testscore may contain a decimal place. (Hint: the main function will need to call the getTestScore function three times.) The main function then should call the calcAverage function to calculate and return the average of the three test scores. When the calAverage function has completed its task, the main function should display the average on the screen.