All of the students at north high school took a benchmark test. when the administration analyzed the students' grades, they found that the grades were normally distributed and that [blank] of the students received grades with z-scores between 0.15 and 0.85.

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3

7 is the median   7.875 is the mean

step-by-step explanation:

3,4,5,6,8,11,13,13

step-by-step explanation:

let pq = qr = rs = x, and xz = y and zu = z.

if the horizontal lines are parallel, then corresponding segments are in proportion:

substitute:

therefore 3 = y = z.

xu = y + z → xu = 3 + 3 = 6