A research organization claims that the monthly wages of industrial workers in district X

Question

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: 1 x = 648, 2
1 s
= 120, and 1 n = 100
District Y: 2 x = 495, 2
2 s = 140, and 2 n = 90
Verify at 0.05 level of significance whether the sample results support the claim of the
organization.

Answer 1

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.