The accompanying data on household expenditures on transportation for the United Kingdom appeared in "Transport Statistics for Great Britain: 2002 Edition" (in Family Spending: A Report on the Family Expenditure Survey [The Stationary Office, 2002]). Expenditures (in pounds per week) included costs of purchasing and maintaining any vehicles owned by members of the household and any costs associated with public transportation and leisure travel.
a. Construct time series plots of the transportation expense data and the percent of household expense data.
b. Do the time series plots of Part (a) support the statement that follows? Explain why or why not. Statement: Although actual expenditures have been increasing, the percentage of the total household expenditures that go toward transportation has remained relatively stable.