An article that appeared in USA Today (Septem ber 3, 2003) included a graph similar to the one shown here summarizing responses from polls conducted in 1978, 1991, and 2003 in which a sample of American adults were asked whether or not it was a good time or a bad time to buy a house.

a. Construct a time-series plot that shows how the percentage that thought it was a good time to buy a house has changed over time.

b. Add a new line to the plot from Part

(a) showing the percentage that thought it was a bad time to buy a house over time. Be sure to label the lines clearly.

c. Which graph, the given bar chart or the time-series plot, best shows the trend over time?