it looks like you’re using a one-sided t-test to get your p-value.
I agree that a two-sided test would be the right thing to use here, and p-value calculations aren’t something I fully understand. Is this calculation one-sided or two-sided?
I can’t tell what’s being done in that calculation.
I’m getting a p-value of 0.108 from a Pearson chi-square test (with cell values 55, 809; 78, 856). A chi-square test and a two-tailed t-test should give very similar results with these data, so I agree with Michael that it looks like your p=0.053 comes from a one-tailed test.
I agree that a two-sided test would be the right thing to use here, and p-value calculations aren’t something I fully understand. Is this calculation one-sided or two-sided?
It looks like the NORMDIST function on your sheet is taking the integral from 0 to
z_score, which is one-sided. A two-sided test would takeI can’t tell what’s being done in that calculation.
I’m getting a p-value of 0.108 from a Pearson chi-square test (with cell values 55, 809; 78, 856). A chi-square test and a two-tailed t-test should give very similar results with these data, so I agree with Michael that it looks like your p=0.053 comes from a one-tailed test.
Yes, you’re right. Sorry! I redid it computationally and also got 0.108. Post updated.