Power of statistical test: probability of rejecting false null hypothesis.
o ‘Reject’ or ‘Fail to reject’ only applies to 0
Estimated sample error (sM):
o s M s/(sqrt. of n)
o Use it when you don’t know σ of population
observed(M-μ)/ s M
If sample size is huge, ‘t’ distance becomes the same as ‘z’ distance.
We estimate population standard deviation with sample standard deviation.
t-distribution is flatter than normal distribution (has heavier tails)
More difficult to reject the null in the tails (critical values are more extreme)
In hypothesis testing, we must know the degrees of freedom to indentify the critical value
critical value score defined by alpha.
If the p value is small, we r