Consider the following hypothesis statement using alpha = .05, and data from two independent samples:
Ho: µ1 - µ2 = 0
Ha: µ1 - µ2 not equal to 0
X1 = 237, X2 = 218
¬1 = 54, ¬2 = 63
n1 = 42, n2 = 35
a) Calculate the appropriate test statistic and interpret the result. b) Calculate the p value and interpret the result.
Ho: mean1 = mean2
Ha: mean1 ≠ mean2
Since these are just samples rather than the whole population, µ is an inappropriate designation. µ is parameter rather than a statistic.
Z = (mean1 - mean2)/standard error (SE) of difference between means
SEdiff = √(SEmean1^2 + SEmean2^2)
SEm = SD/√n
If only one SD is provided, you can use just that to determine SEdiff.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.