The table shows the height of a plant as it grows. a. model the data with an equation. b. based on your model, predict the height of the plant at 12 months.
x
3
5
7
9
y
15
25
35
45

a) Differences between x-values are constant (2), and differences between y-values are also constant (10), so the model can be a linear equation. It will have a slope of (10)/(2) = 5. We can use any of the table value pairs in the pont-slope form of the equation:
  y = 5(x -3) +15
or
  y = 5x

b) The model predicts the height at 12 months will be
  y = 5·12
  y = 60


We assume x represents months. The units for y are not given in this problem statement.