The number of Hybrid vehicles sold weekly at a local car lot increased from 11 in 2006 to 19 in 2008. Predict the number of Hybrid vehicles sold weekly in 2011.

Question

My answer:
rate = 19 - 11
2008 - 2006
rate = 8
2
rate = 4
then I subtracted 2011 from 2008 got 3 and multiplied that by 4 to get
12 as the # of cars a wk per yr. increase. Is this right?

Answer 1

You really should write a linear equation:
You're right on calculating the rate. It is 4. You can also call that the slope of the line. In y=mx+b form,
y=4x+b Since you started at 11 in 2006, 11 is your y-intercept (b)
y=4x+11
Again, since you started at 2006, 2011 is 5 years from that so plug in 5 for x.
y=4*5+11=31.
Does this make sense or did you not start linear equations yet??