Science and Mathematics for Engineering 6th Edition by John Bird

Exercise 2

Corresponding values obtained experimentally for two quantities are:
$$\begin{array} { r r r r r r r } x & - 5 & - 3 & - 1 & 0 & 2 & 4 \\y & - 17 & - 11 & - 5 & - 2 & 4 & 10\end{array}$$
Plot a graph of $\mathrm { y }$ (vertically) against $\mathrm { x }$ (horizontally) to scales of $1 \mathrm {~cm} = 1$ for the horizontal
axis and $1 \mathrm {~cm} = 2$ for the vertical $y$ -axis.
From the graph find: (a) the value of $y$ when $x = 3$
(b) the value of $y$ when $x = - 4$
(c) the value of $x$ when $y = 1$
(d) the value of $x$ when $y = - 20$