16. Millionaires: The ages of the 36 millionaires sampled are arranged in increasing order in the following table.

31 38 39 39 42 42 45 47 48

48 48 52 52 53 54 55 57 59

60 61 64 64 66 66 67 68 68

69 71 71 74 75 77 79 79 79

a. Determine the quartiles for the data.

b. Obtain and interpret the interquartile range.

c. Find and interpret the five number summary.

d. Calculate the lower and upper limits.

e. Identify potential outliers, if any.

f. Construct and interpret a boxplot and, if appropriate, a modified boxplot.

18. Gasoline prices. The US Energy Information Administration reports figures on retail gasoline prices in the Monthly Energy Review. Data are obtained by sampling10,000 gasoline service stations from a total of more than 185,000. For the 10,000 stations sampled in June 2003, the meanprice per gallon for unleaded regular gasoline was $1.49.

a. Is the mean price given here a sample mean or a population mean? Explain your answer.

b. What letter or symbol would you use to designate the mean of $1.49?

c. Is the mean price given here a statistic or a parameter? Explain your answer.

20. Millionaires. Refer to date in problem 16. Use the technology of your choice to obtain

a. a modified boxplot for the data.

b. the five number summary of the data.

Answers questions on arranging data, Quartiles, Box plot, Mean