FILE The following table lists a portion of the percentage (share)

of total shipment of music that falls in the category of country and rap/hip-hop rock music from 1990–2008. The complete data set is on the text website, labeled Country and Rap.

Year Country (in %) Rap/Hip-hop (in %)

1990 9.6 8.5 1991 12.8 10.0

⋮ ⋮ ⋮

2008 11.9 10.7 SOURCE: www.riaa.com.

a. Plot each of the above series and comment on the respective trend.

b. Estimate a linear, a quadratic, and a cubic trend model for the share of country music in the United States. Use their adjusted R2 to choose the preferred model and with this model make a forecast for 2009.

c. Estimate a linear, a quadratic, and a cubic trend model for the share of rap/hip-hop music in the United States. Use their adjusted R2 to choose the preferred model and with this model make a forecast for 2009.