Scenario: We’ll continue to examine the World Development Indicators data in BirthRate 2005. This time we’ll see if we can use a normal model to represent one or more variables.

a. Complete the steps necessary to create a normal quantile plot for the Fertil column. Fertil is the mean number of children that women have during their child-bearing years in each country. Report on what you see in the graph and what you conclude about the suitability of a normal model.

b. Consider a random variable X ~ N(2.993, 1.590). Such a variable has the same mean and standard deviation as Fertil. For Fertil, 10% of observations fell below 1.319 children. What proportion of X lies to the left of 1.319?

c. Using the same X, find Pr(X > 5.5).Compare your result to the observed data for Fertil.

d. Find the third quartile for X and compare the result to the third quartile for Fertil.