An infinite population has a mean of 40 and a standard deviation of 15.A sample of size 100 is taken at random from this population.The standard error of the sample mean equals:
A)15
B)15/√100
C)15/100
D)None of these choices.

Question

Quizplus · Accepted Answer

The standard error of the sample mean is equal to the standard deviation of the population divided by the square root of the sample size. Therefore, the standard error of the sample mean=15/√100=1.5. Choice A is incorrect because it gives the standard deviation of the population instead of the standard error of the sample mean. Choice C is incorrect because it gives a value that is too small to be the standard error of the sample mean. Choice D is incorrect because there is a correct answer.

An Infinite Population Has a Mean of 40 and a Standard