Question re: Elan QM practice problem test, direction, hypothesis, practice, critical

dkishore1

I’ve been working through some practice problems with Elan and had a question about a few problems in reading 11, hypothesis testing.
Looking at the answers to problems 2426 in Reading 11, I’m solid getting through the test statistic but I keep getting tripped up on getting the right critical values and it throws my answer off.
If we take a look at problem 26 for example, can someone explain how they come up with a zcritical value of 1.285?
Thanks for any direction you can provide!