So I’m unable to get the correct p-value for the 2nd question on the hypothesis testing -01 section, and i’m unsure why.
My question states:
You wish to test the following claim(H_a) at a significance level of alpha =0.002
H_o : mu = 86.7
H_a : mu > 86.7
You believe the population is normally distributed, but you do not know the standard deviation. You obtain a sample of size n=20, with mean M=105.3, and a standard deviation of SD=20.8
What is the p-value for this sample? (Report answer accurate to four decimal places.)
The formula I am using is (barx-M) / (SE) to find the z-score. Then I am looking at the propability tables and finding the p-value.
After plugging in all of the numbers I ended with SE= 20.8/sqrt20 =4.65 so the z-score formula was (105.3-86.7)/4.65=4
The z-score of 4 corresponds with a p-value greater than or equal to 0.9998.
This is not accepted as the right answer, and I have done about 10 of these, so am I just using the wrong formula? Or did I put a value in the wrong place?
Any help is appreciated
