Hypothesis testing for difference between the two population means.

An article studied the relationship between voluntary organizational turnover and such factors as work performance, work satisfaction, and company tenure. As part of the study, article's authors compared work performance ratings for "stayers" (employees who stay in their organization) and "leavers" (employees who voluntarily quit their jobs). Assume that a random sample of 175 stayers has a mean performance rating (on a 20-point scale) of x-bar1 = 12.8, and that a random sample of 140 leavers has a mean performance rating of x-bar2 = 14.7. Imagine that these random samples are independent and that σ1 = 3.7 and σ2 = 4.5:

Let μ1 be the mean performance rating for stayers, and let μ2 be the mean performance rating for leavers. Use the sample information to find out a 99 percent confidence interval for μ1 - μ2. [ ]

Set up the appropriate null and alternative hypotheses essential to try to establish that the mean performance rating for leavers is higher than the mean performance rating for stayers:

Ho: [ ]
Ha: [ ]

What is the rejection point at α = .01 and indicate if you would accept or reject Ho? [ ]