After a somewhat uncertain start, e-commerce sales in the United States have been growing for the past several years. Shown below are quarterly e-commerce sales figures ($ billions) released by the...

After a somewhat uncertain start, e-commerce sales in the United States have been growing for the past several years. Shown below are quarterly e-commerce sales figures ($ billions) released by the Census Bureau for the United States over a three-year period. Use these data to determine the equation of a trend line fore-commerce sales during this time and use the trend “model” to forecast e-commerce sales for the third quarter of the year 2010.