x will be the year.
where x=0 represents the year 1950.
n 1950, the population density of the United States was 42.6 people per sq mile and in 2000 it was 79.6 people per sq mile. Assuming the population density grew at a constant rate of change, find the function that gives the population density based on the number of years since 1950.
So far all I have gotten is y = .74x but I know I need it in y =.74x + b. I just can't figure out the +b part!
Also, would x = the year?