What is the value of x?

Enter your answer, as a decimal, in the box.

Step-by-step explanation:

The following ratio solves the problem

AM/MN = x / MP

(67.2 - 32) /67.2 = x / 81.9

35.2 / 67.2 = x / 81.9

Cross Multiply

67.2 * x = 81.9 * 35.2

67.2 x = 2882.88

Divide by 67.2

x = 2882.88 / 67.2

x = 42.9

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.