Question

Suppose your marketing colleague used a known population mean and standard deviation to compute the standard error as 56.8 for samples of a particular size. You don't know the particular sample size but your colleague told you that the sample size is greater than 60. Your boss asks what the standard error would be if you triple the sample size. What is the standard error for the new sample size?

Answer 1

32.793

Explanation:

Given that your marketing colleague used a known population mean and standard deviation to compute the standard error as 56.8 for samples of a particular size

You don't know the particular sample size but your colleague told you that the sample size is greater than 60.

When n becomes 3n, we get Std error would become instead of
`(std dev)/(√(n) )`

to
`(std dev)/(√(3n) )`

Thus we get standard error for new sample size = old se/sqrt 3

=
`(56.8)/(√(3) ) \\=32.793`