Question

Suppose you are looking at the population of 8,000 students that are freshman at college. You want to determine on average how many hours a week they work each week. Let’s call that number ?. You decide to take a sample of 100 of them.

Let’s just say the standard deviation of those 8,000 students is 5.

1) What is the formula for standard deviation of a population the 8,000 students (please make sure the summation sign has a starting and ending number)? Can it ever be negative? In our example, what are the units of the standard deviation?

2) What does the Central Limit Theorem say about the standard deviation of the curve discussed in question 5) above?

3) What is the standard deviation in our example?

4) What is the probability that a randomly picked sample has a point estimate within .5 of the actual mean ??

5) What is the probability that a randomly picked sample has a point estimate within 1 of the actual mean ??

6) Do you know whether our point estimate is higher or lower than the mean?

Answer 1

thank you