Question

The grades on the last art exam had a mean of 75%. Assume the population of grades on art exams is known to be distributed normally, with a standard deviation of 7%. Approximately what percent of students earn a score between 75% and 82%?


A. 37.2%

B. 84.1%

C. 34.1%

D. 50%

Answer 1

I know the answer is 34.1%, but I don't understand how to get to that conclusion.

Answer 2

do you have a calculater?

Answer 3

Yes.

Answer 4

@zepdrix @.Sam. @Whitemonsterbunny17 Please help?

Answer 5

@uri @Vocaloid Help explain?

Answer 6

are you familiar with the 68-95-97 rule?

Answer 7

Sounds familiar... But no. I can't recall.

Answer 8

it's a rule for normal distributions (like the one above)

it tells us what percentage of data should fall between what values, depending on standard deviation

Answer 9

it works like this

Answer 10

Ok! I've seen that in my lessons.