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. Is it more or less than .05?
A research organization claims that the monthly wages of industrial workers in district X exceeds that of those in district Y by more than Rs 150. Two different samples drawn independently from the two district yielded the following results:
District X: x1 = 648, s12 = 120, and n1 = 100
District Y: x2 = 495, s22 = 140, and n2 = 90
Verify at 0.05 level of significance whether the sample results support the claim of the organization.
1 answer