Finding Young's modulus from a force-extension test

In a Searle's apparatus test, loads were added to a wire $2.2\ \text{m}$ long and $0.70\ \text{mm}$ across, and each stretch was read on a screw gauge. Real readings scatter a little. You will make the program fit the best straight line, and get Young's modulus from its slope.

The idea. $F = \dfrac{YA}{L}\Delta L$, so a graph of load against stretch is a straight line of slope $\dfrac{YA}{L}$. Then $Y = \text{slope} \times \dfrac{L}{A}$.

Your tasks.

1. Work out the area A of the wire's cross-section, in square metres.
2. Fit a straight line to load against stretch (in metres), and find its slope in N/m.
3. Work out Young's modulus Y. Which metal is it?