Can someone answer these Stat questions? I am having trouble with these two.?

Question

5. A sample of 40 observations is selected from one somewhat normal population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second source. The sample mean was 99 and the standard deviation was 6. Conduct a test of the hypothesis using the .04 level of significance.

6. The Rocky Mountain district sales manager of JCM, Inc., a college book publishing company, claims that each of his sales representatives makes 40 calls on professors per week. Several reps said that this estimate is too low. To research the claim, a random sample of 28 reps revealed that the mean number of calls made last week was 42. The standard deviation of the sample was computed to be 21 calls. At the .05 level of significance, can we conclude that more than 40 calls are made on the average in a week?

Answer 1

5. First off, you need a hypothesis. Your hypothesis would be something to the effect of
Ho the means are equal
Ha the means are not equal.
Next you'd find the critical level for your test statistic, this would come from your alpha = .04
Finally, you'd compute the test statistic, and compare it to the critical level. You can think of this as checking to see if your test statistic is further out along the normal curve than your critical level. If it is, then you can reject Ho at .04 significance. Note: you NEVER accept Ha, you only reject Ho.

6. For this one, your hypothesis would be
Ho the mean is 40
Ha the mean is less than 40, Your procedure would be as before.
Writing out the relevant formulas would not do so well here, but I can find them for you with additional explanations...
http://davidmlane.com/hyperstat/logic_hypothesis.html
http://wise.cgu.edu/hypothesis/
http://wise.cgu.edu/hypothesis/tutorial1.html
http://simon.cs.vt.edu/SoSci/Site/T-Dist/

To find tutorials on any subject just put (subject) tutorial in your search window. I found these by searching on hypothesis testing tutorial