Which value in this data set is an outlier? 4, 5, 1, 7, 4, 5, 8, 9, 6, 5, 4, 9, 7 1 2 3 9

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%)