The mean of all possible sample means of a given sample size is the same as the
mean of the population.
So the mean of the sampling distribution of sample means with sample size 247 is
the same as the population mean, 82.
The standard deviation of all possible sample means of a given sample size, n,
is the standard deviation of the population DIVIDED BY the square root of n.
So the standard deviation of the sampling distribution of sample means with
sample size 247 is the population standard deviation, 30, DIVIDED BY √247.
Answers:
The mean of a sampling distribution of sample means with sample size 247 is:
The standard deviation of a sampling distribution of sample means with sample size 247 is:
[round that off as you were instructed.]
Edwin