If random samples of size 40 are taken from all countries of

If random samples of size 40 are taken from all countries of the world, what is the mean and standard deviation of the distribution of means of all such samples? What about a random sample size of 80?

The AllCountries dataset includes land area, in square kilometers, for all 1,766,860. If random samples of size 40 are taken from all countries of the world, what is the mean and standard deviation of the distribution of means of all such samples? What about a random sample size of 80? 608,120 sq km with standard deviation 94, 080 sq km and the mean is 213 countries in the world. The median land area for all the countries is

Solution

In a random sample of 40,

The mean will be the same as the population mean, which is 608,120.

The standard deviation will be the population standard deviation divided by the square root of the sample size, 1,766,860/square root of 40 = 279,365.0953

For a random sample of 80,

The mean will be the same as the population mean, which is 608,120.

The standard deviation will be the population standard deviation divided by the square root of the sample size, 1,766,860/square root of 80 = 197,540.9533