Question: Between test 1 (score of 230 and mean of 210 and standard deviation of 22) and test 2 (score of 80 and mean of 70 and standard deviation of 8), which one is better? Explain your reasoning.

Question

I know that test 2 is better. I am not good at giving the reasoning but I think that it is due to how closer the score is to the mean.

Answer 1

what do you mean by "better"? Closer to the mean?
Farther above the mean -- more std away?

In any case, check the number of std from the mean; that's probably the first step.

Answer 2

Nevermind it is test 2.
Test 1= z220=220-200/21=20/21=0.95=.33
Test 2= z90=90-80/8=10/8=1.25=.40

Answer 3

your : Test 1= z220=220-200/21=20/21=0.95=.33

doesn't even match the data given in the question.

prob(x < 230)
z-score = (230 - 210)/22 = .9091

your ... = 0.95 = .33 makes no sense