The point-slope form:

We have the slope m = 4 and the point (-1, -3). Substitute:

83, 85, 89, 92, 95 it should be this
The 'template' for a quadratic function is:

, where <em>a</em> is the vertical stretch/compression factor.
If the <em>a</em> in f(x) is 2/5, then vertically stretching the function is done by multiplying the function by 2, making:
Multiply 9 feet times 12 inches and you get 108 inches. Then take 108 inches and divide it by 12 sections, you get 9 inches.
Answer: Each section should be 9 inches long, or 0.75, or 3/4 feet long.