Suppose your marketing colleague used a known population mean and standard deviation to compute the standard error as 56.4 for samples of a...

Suppose your marketing colleague used a known population mean and standard deviation to compute the standard error as 56.4 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 70. 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?

Please round your answer to the nearest tenth.