Use A(n) = A(1)r ^n − 1 to find the 7th term in the sequence.

6, 12, 24, 48, …

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%)