1. The mean selling price of new homes in a small town over a year was $115,000. The population standard deviation was $25,000. A random sample of 100 new home sales from this city was taken.

a) What is the probability that the sample mean selling price was more than $110,000?

b) What is the probability that the sample mean selling price was between $113,000 and $117,000?

c) What is the probability that the sample mean selling price was between $114,000 and $116,000?

2. According to a survey, only 15% of customers who visited the web site of a major retail store made a purchase

random samples of size 50 are selected.

a) What is the mean of all the sample proportions of customers who will make a purchase after visiting the web site?

b) What is the standard deviation of all the sample proportions of customers who will make a purchase after visiting the

web site?

c) What proportion of all possible samples will have between 20% and 30% of customers who will make a purchase after

visiting the web site?

d) What proportion of all possible samples will have less than 15% of customers who will make a purchase after visiting the

web site?