10.1 Two Population Means with Unknown Standard Deviations
Standard error SE =
Test statistic (t-score) t =
Degrees of freedom
s1 and s2 are the sample standard deviations, and n1 and n2 are the sample sizes.
and are the sample means.
Cohen’s d is the measure of effect size
10.2 Two Population Means with Known Standard Deviations
Test statistic (z-score)
10.3 Comparing Two Independent Population Proportions
Pooled proportion pc =
Distribution for the differences
where the null hypothesis is H0: pA = pB or H0: pA – pB = 0.
Test statistic (z-score):
where the null hypothesis is H0: pA = pB or H0: pA − pB = 0
p′A and p′B are the sample proportions, pA and pB are the population proportions,
Pc is the pooled proportion, and nA and nB are the sample sizes.
10.4 Matched or Paired Samples (Optional)
Test statistic (t-score): t =
is the mean of the sample differences, μd is the mean of the population differences, sd is the sample standard deviation of the differences, and n is the sample size.