√
(
6

5
)
2


square root of, left parenthesis, start fraction, 5, divided by, 6, end fraction, right parenthesis, start superscript, 2, end superscript, end square root =

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%)