Develop an M-file function that is passed a numeric grade from 0 to 100 and returns a lett...

Develop an M-file function that is passed a numeric grade from 0 to 100 and returns a letter grade according to the scheme:

The first line of the function should be

function grade = lettergrade(score)

Design the function so that it displays an error message and terminates in the event that the user enters a value of score that is less than zero or greater than 100. Test your function with 89.9999, 90, 45 and 120.