Please Help :( Find x so that m||n (m is parallel to n). Identify the postulate or theorem you used.

I just need help on 16, 18, and 20. Please

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.

the answer is a, biohazard symbol

x^2 + 10x + 38 + 161/x-4

to find this, you'll need to synthetically divide using synthetic division.

here's how you would set it up:

4 is what you're dividing by (set x -4 = 0)

the numbers you are 'dividing' by are 1, 6, -2, and 9 or the coefficients of the terms listed above.

bring the first term down (1), multiply that by 4 before raising it to the next term to add (6). repeat this process as so:

6 + 4 = 10; 10 x 4 = 40; 40 - 2 = 38 x 4 = 152 + 9 = 161

161 is over x-4 as there are now two constants and you cannot combine them.

also, i'm not sure if it was -9 or +9, so i assumed.

hope this !