In the population, “intelligence quotient” scores (iq’s) are approximately normally distributed with a mean of 100 and a standard deviation of 15. suppose we plan to obtain iq scores of a random sample of n = 30 individuals, and then we’ll compute the sample mean and sample standard deviation. suppose you were unsure of the value of the population standard deviation, and so you plan to use only the sample standard deviation. find the exact probability that the sample mean will be within one-third of one sample standard deviation of the population mean.

is there a picture

step-by-step explanation:

x-3y=4

step-by-step e

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.

it's d

step-by-step explanation: