please solve A through D

4. Energy Use per Dollar GDP Source: U.S. Department of Energy Energy use per dollar of GDP indexed to 1980 means that energy use for any year is viewed as a percent of use per dollar of GDP in 1980. The following data show the energy use per dollar of GDP, as a percent, for selected years from 1985 and projected to 2035. a. Look at a scatterplot of this data. Do you think a linear model would fit this data? Do you think a quadratic model would fit this data? Do you think a cubic (x3) model would fit this data? b. Find a linear function that models these data, with x equal to the number of years past 1980 and y equal to the energy use per dollar of GDP, as a percent. Write it here: c. Find a cubic function that models these data, with x equal to the number of years past 1980 and y equal to the energy use per dollar of GDP, as a percent. Write it here: d. Use a leaner model and find the energy use per dollar of GDP in year 2040. Write it here: Use a cubic model and find the energy use per dollar of GDP in year 2040. Write it here: Which model indicates that the percent of energy use may increase after 2035