Life Expectancy Part 2 Refer to the Data Set AllCountries. (Data sets can be found by clicking the textbook link on the StatKey main page. Here is a direct link to the 3rd Edition Data Sets: http://www.lock5stat.com/datapage3e.html.) Use the 199 life expectancies listed (there are some missing values) and StatKey to answer the following questions.

a. What is the population? (Hint: Do we know the life expectancy of every country?)

b. From the AllCountries data, do your best to randomly select 10 of the 199 life expectancies listed. List the 10 values you selected below.

c. Use StatKey to produce a bootstrap distribution for the average life expectancy using the 10 values selected in part b. Take at least 1000 bootstrap samples. Use the "Two-Tail" box in StatKey to find the cut-off values for a 95% confidence interval for the average life expectancy of all countries. Express your answer as an interval and include units. Take a screenshot of your StatKey page, and paste it below. (See the link: https://sites.google.com/site/lock5stat/copying-output-from-statkey for help. Your dotplot will differ from other students.)

d. What does one bootstrap sample consist of? How large is each sample size?

e. What population parameter are we trying to estimate? Describe this population parameter in plain words.

f. Explain why this is using a bootstrap technique.

g. Use the output from StatKey to find the mean and standard error of the bootstrap distribution.

h. Use the mean and standard error of the bootstrap distribution to create a 95% confidence interval for the average life expectancy of all countries. Express your answer as an interval and

include units.

i. Are the confidence intervals you found in parts c and h the same? Should they be?

j. You found the mean life expectancy of the data from AllCountries in question 2b from Graded Problem Set 2. Does your confidence interval contain this mean? Should it?

m. What factors might affect your answer from part j above?

Use the crop yields (in pounds per acre)from the samples of regular seed & kiln-dried seed listed in the table below to answer the following questions.

Regular	1903	1935	1910	2496	2108	1961	2060	1444	1612	1316	1511
Kiln Dried	2009	1915	2011	2463	2180	1925	2122	1482	1542	1443	1535

Use StatKey to create a 95% bootstrap confidence interval for the difference in mean yield. Take a screenshot of your StatKey page, and paste it below. (Your dotplot will differ from other students.)

Explain what a value of 0 in the StatKey bootstrap would mean in the context of this problem. Does your confidence interval contain the number 0?

Do the crop yields appear to be substantially different for the regular seed & kiln-dried seed? Does one seed appear to be better?