Computer programs can automatic routine tasks. Write just a method named get Passing LetterGrade () that takes a real number (for example, 85.5) and returns a string with a single letter in it. Use the following criteria: Grade Letter 90+ A B 80- 89.9 70- 79.9 IC If the grade is not in any of the above 3 ranges, then return an empty string. Examples: getPassingLetterGrade ( 85.5 ) returns "B" getPassingletterGrade ( 67.8 ) returns an empty string get PassingLetterGrade ( 91.2 ) returns "A" get Passing LetterGrade ( 78.9) returns "C