Why do you need to know the sampling distribution of the difference between two sample means in

Question:

Why do you need to know the sampling of the difference between two sample means in order to perform a hypothesis test to compare two population means?
Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...