How many M&Ms must be sampled to construct the 95% confidence interval for the proportion of yellow M&Ms in that bag if we want a margin of error of ± .12? (note that the z-score was rounded to three decimal places in the calculation)

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%)