Answer to question 4

This question concerns the sampling distribution of the sample mean, , for n = 50, when drawing from the population specified in question 3. This distribution has the standard error

Again use z-scores, but this time of the form

So

and the answer is then

Compare the answers to questions 3 and 4. There is almost a 10 per cent chance that a single randomly selected student will have a height outside the range 63 to 73 inches, but if we draw a sample of 50 students there is practically no chance that the average height of these 50 students will lie outside of the 63 to 73 inch range.

Here you may return to the question.