Help me solve this mathdoku please. Rules: You can only use 1 digit numbers, (excluding 0 and 1), you can only use one number once, and everything must be fit in. PLEASE HELP (IGNORE NUMBERS I PUT!!)

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)