The average teacher's salary in North Dakota is $41,027. Assume a normal distribution with standard deviation of $5200.
A. what is the probability that a randomly selected teachers salary is less than 40,000?

B. What is the probability that the mean for a sample of 80 teachers' salaries is greater than 42,000

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asked by Jasmin
  1. A. Use same process as previous post.

    B. Now we are talking about a distribution of means rather than raw scores.

    Z = (score-mean)/SEm

    SEm = SD/√n

    Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.

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    posted by PsyDAG

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