So I need help pls show ur work

x = – ⅓

Step-by-step explanation:

The solution to the expression can be obtained as follow:

–3.1x + 7 – 7.4x = 1.5x – 6(x – 3/2)

Clear bracket

–3.1x + 7 – 7.4x = 1.5x – 6x + 9

–3.1x – 7.4x + 7 = –4.5x + 9

–10.5x + 7 = –4.5x + 9

Collect like terms

–10.5x + 4.5x = 9 – 7

–6x = 2

Divide both side by –6

x = 2 / –6

x = – ⅓

Thus, the solution to the equation is –⅓

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.