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The population mean annual salary for environmental compliance specialists is about ​$60 comma 500. A random sample of 32 specialists is drawn from this population. What is the probability that the mean salary of the sample is less than ​$57 comma 500​? Assume sigmaequals​$6 comma 400.

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Answer:

0.004 is the probability that the mean salary of the sample is less than ​$57,500.

Explanation:

We are given the following information in the question:

Mean, μ = $60,500

Standard Deviation, σ = $6,400

Sample size, n = 32

Formula:


z_(score) = \displaystyle(x-\mu)/(\sigma)

Standard error due to sampling =


=(\sigma)/(√(n)) = (6400)/(√(32)) =1131.37

P(mean salary of the sample is less than $57,500)


P( x < 57500) = P( z < \displaystyle(57500 - 60500)/(1131.37)) = P(z <-2.6516)

Calculation the value from standard normal z table, we have,


P(x < 57500) = 0.004

0.004 is the probability that the mean salary of the sample is less than ​$57,500.

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