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The eighth-grade students at a large school district took a standardized math exam. Suppose that the...

The eighth-grade students at a large school district took a standardized math exam. Suppose that the scores were normally distributed with mean 77 and standard deviation 12. A sample of 30 scores is randomly selected.

(a)

Find the mean of the sampling distribution of the mean scores from samples of size 30.

μx =

(b)

Find the standard deviation of the sampling distribution from part (a). (Round your answer to three decimal places.)

σx =

Math   Statistics-And-Probability   
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Answer #1

Solution :

Given that ,

mean = = 77

standard deviation = = 12

n = 30

(a)

sampling distribution of the mean   =

(b

standard deviation of the sampling distribution

=  / n = 12/ 30=2.191

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