Find the value of f(6). y
y = f(x)
K
10
8
6
4
-10
-8
-6
-4
-2
4
6
8
10
-2
-4
-6
-8
-10

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%)