A variable of two populations has a mean of 40 and a standard deviation of 12 for one of the populations and a mean a of 40 and a standard deviation of 6 for the other population. Moreover, the variable is normally distributed on each of the two populations.
a. For independent samples of sizes 9 and 4, respectively, determine the mean and standard deviation of X1-X2. (See attachment for full questions).© BrainMass Inc. brainmass.com March 4, 2021, 6:07 pm ad1c9bdddf
In this solution, the mean and standard deviation of the difference of two independent normal random variables is found. Then a hypothesis about the new random variable is tested.