A data set consists of the five numbers 3, 4, 7, x and y. The mode and mean of this set are 4 and 6.5 respectively. Find x and y and the median of the set.

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%)