1. Find the slope of the line through the points (4, 4) and (8, 7).
2. Find the slope of the line through the points (-3, 2) and (5, 2).
3. Given $f(x) = 3x^2$, find the slope of the secant line through the points (1, $f(1)$) and (4, $f(4)$) on the graph of $y = f(x)$.