A population has a mean mean=77 and a standard deviation =20. :D?

2017-12-11 1:22 pm

A population has a mean=77 and a standard deviation =20. Find the mean and standard deviation of a sampling distribution of sample means with sample size N =247.

更新1:

Last one for the night :D

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用戶122084

2017-12-11 1:52 pm

✔ 最佳答案

OK, here you go sweetheart :)

Oh, hey Kei !!!!!!!!!!!!!!!!!!!!!!!!!!!

We are given μ = 77, σ = 20

The Central limit theorem states that for the sampling distrubtion 'X', to be normal, n > 30. Since n = 247, we can assume that we are dealing with data that is normally distributed!

The mean is :
μ = 77

The standard deviation is :
σ = σ/√n = 20/√247 ≈ 1.2726 (to 4dp)

Hope this helps !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
P.S. (Don't forget to vote me best answer as being the first to correctly answer your question!) ☺

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