The population of the US was about 180 million in 1960, grew to 206 million in 1970, and 226 million in 1980.

(a)Assuming that the population was growing exponentially, use logarithms and the method of least squares to estimate the population in 1990.

(b)According to the national census, the 1990 population was 249 million. What does this say about the assumption of exponential growth?

(c)Predict the population in the year 2010.