The Professor's Response

(This is in my H.W 9.1 Testing the Differences Between Two Means: Using z Test)
Teachers' Salaries: California and New York lead the list of average teachers' salaries. The California yearly average is $64,421 while teachers in New York make an average annual salary of $62,332. Random samples of 45 teachers from each state yielded the following:

-Sample Mean = 64,510
-Population Standard Deviation=8,200

New York:
-Sample Mean= 62,900
-Population Standard Deviation= 7,800

  See the professor's answer below.

Professor McGukian

Hi Stephanie,

In the question that you posted, you did not specify what the problem is asking you to do, so I assumed a basic hypothesis test. However, you could arrive at the same conclusion using a confidence interval. In either case, you should watch the video below of me solving this problem. 

There are several videos on this topic in Chapter 9, section 2. Confidence intervals for this kind of problem are covered in section 9.1.


Let me know if you need anything else,

Professor McGuckian 

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