A personnel director in a particular state claims that the mean annual income is greater in one of the​ state's counties​ (county A) than it is in another county​ (county B). In County​ A, a random...

A personnel director in a particular state claims that the mean annual income is greater in one of the​ state's counties​ (county A) than it is in another county​ (county B). In County​ A, a random sample of 12 residents has a mean annual income of $42,000 and a standard deviation of $8700. In County​ B, a random sample of 10 residents has a mean annual income of $39,200 and a standard deviation of $5700. At α=0.005​, answer parts​ (a) through​ (e). Assume the population variances are not equal. If​ convenient, use technology to solve the problem.

Enter the critical​ value