Instructions: In one Excel le create two sheets. Label one sheet \Problem 1" and label the second
sheet \Problem 2." Your solutions to the two problems should be recorded on the corresponding
sheet. Additionally, you should clearly label each part of the problems with (a), (b), etc., and every
computation should be labeled. For example, in the cell next to the mean of the data, you should
have typed the word mean or average.
Please make sure to do your computations using Excel. Do not do computations using Tables As
and C or on a calculator and then type the answers into Excel.
See the accompanying data sheets for the following problems.
1. (10 points) The data in the le facebookfriends.xls gives the number of friends for a
simple random sample of Facebook users. Use a 95% con dence interval to estimate
the mean number of Facebook friends.
2. Most professional athletes will agree that resources (money, equipment, etc.) matter
when it comes to success in sports. One way to measure a country’s success in sports
would be to count the total number of medals won by athletes from a country in the
Olympics. We know that the average number of medals won by countries in the 2012
Summer Olympics was 11.4. Countries not classi ed as rst world countries have fewer
resources to aid in the training of their athletes. A random sample of countries with
fewer resources was chosen and the total medal count from the 2012 Summer Olympics
was recorded.
(a) (5 points) Consider the question: Do countries with fewer resources win fewer
medals in the Olympics? State the null and alternative hypotheses relative to this
question.
(b) (5 points) Find the t test statistic.
(c) (5 points) What is the P-value for your t?
(d) (5 points) Is the data signi cant at signi cance level = 0:05?