In each of the next set of problems, assume that the data can be modeled by a straight line and that the trend continues indefinitely. Use two data points to find such a line and then answer the question

Forrester Research Inc Estimated the amount of online retail sales to be $132.1 billion in 2006 $271.1 billion in 2010. Let X=0 correspond to 2006, and estimate the online sales of music and video in 2012