The 5 participants in a 200-meter dash had the following finishing times in seconds). 25, 26, 30, 28, 26

Assuming that these times constitute an entire population, find the standard deviation of the population. Round your answer to two decimal place

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%)