World Series. The World Series in baseball is won by the first team to win four games (ignoring the 1903 and 1919–1921 World Series, when it was a best of nine). From the document World Series History on the Baseball Almanac website, as of November 2013, the lengths of the World Series are as given in the following table.

Number Relative of games Frequency frequency 4 21 0.200 5 24 0.229 6 24 0.229 7 36 0.343 Let X denote the number of games that it takes to complete a World Series, and let Y denote the number of games that it took to complete a randomly selected World Series from among those considered in the table.

a. Determine the mean and standard deviation of the random variable Y . Interpret your results.

b. Provide an estimate for the mean and standard deviation of the random variable X. Explain your reasoning