The accompanying data on household expendi- tures on transportation for the United Kingdom ap- peared in "Transport Statistics for Great Britain: 2002 Edition" (in Family Spending: A Report on the Family Expenditure Survey [The Stationary Of?ce, 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.
|
Year
|
AverageTransportation
|
Percentage
of HouseholdExpenditures
for Transportation
|
|
1990
|
247.20
|
16.2
|
|
1991
|
259.00
|
15.3
|
|
1992
|
271.80
|
15.8
|
|
1993
|
276.70
|
15.6
|
|
1994
|
283.60
|
15.1
|
|
1995
|
289.90
|
14.9
|
|
1996
|
309.10
|
15.7
|
|
1997
|
328.80
|
16.7
|
|
1998
|
352.20
|
17.0
|
|
1999
|
359.40
|
17.2
|
|
2000
|
385.70
|
16.7
|
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 state- ment that follows? Explain why or why not. Statement: Although actual expenditures have been in- creasing, the percentage of the total household expenditures that go toward transportation has re- mained relatively stable.