The grades on the last history exam had a mean of 80%. assume the population of grades on history exams is known to be distributed normally, with a standard deviation of 5%. approximately what percent of students earn a score between 70% and 80%?

a. 2.2%
b. 10%
c. 47.7%
d. 50%
e. 52.5%

Solve for n? [tex]z = \frac{3}{4} mn[/tex]

Abag contains 3 red marbles, 2 blue marbles, and 2 green marbles. one marble is picked, then another marble. assume that the selections are made with replacement. a) find the probability of picking two red marbles with replacement. b) find the probability of picking a red marble and a blue marble. assume the selections are made without replacement. c) find the probability of picking two red marbles without replacement. d) find the probability of picking a red marble and a blue marble without replacement.

Which shows the graph of the solution set of 3y – 2x > –18?