for step 2 at 22:52 how did you get 146 students who get anxiety and 75 that didn't. shouldn't it be .62*220=137 who felt anxiety and .38*220 students who did not feel anxiety?
You are correct. I should have based the expected successes and failures on the null proportion of 0.62. I used the successes and failures from the sample, which is what you would have to use in a confidence interval where there is no null proportion. Sometimes I just get so used to doing that. Thanks for pointing this out!!!
Very nice video one question though i always mix up with is with the standard deviation why do we use p and not phat in the formula if we are trying to get the standard dev. of p hat? Shouldn't we use its own proportion for its own SD
because in a test we have to assume the given popualtion proportion is correct, even if we think it is something high or lower we need to assume the given value is right, so we use p for standard deviation.
for step 2 at 22:52 how did you get 146 students who get anxiety and 75 that didn't. shouldn't it be .62*220=137 who felt anxiety and .38*220 students who did not feel anxiety?
You are correct. I should have based the expected successes and failures on the null proportion of 0.62. I used the successes and failures from the sample, which is what you would have to use in a confidence interval where there is no null proportion. Sometimes I just get so used to doing that. Thanks for pointing this out!!!
Very nice video one question though i always mix up with is with the standard deviation why do we use p and not phat in the formula if we are trying to get the standard dev. of p hat? Shouldn't we use its own proportion for its own SD
because in a test we have to assume the given popualtion proportion is correct, even if we think it is something high or lower we need to assume the given value is right, so we use p for standard deviation.
such an amazing video! super helpful😀