A wire 2.6 m long and 1.1 mm across carries 75 N and becomes 1.0 mm longer…

Step 1. Area. $A = \pi(0.55 \times 10^{-3}\ \text{m})^2 = 9.50 \times 10^{-7}\ \text{m}^2$.

Step 2. Stress. $\dfrac{75\ \text{N}}{9.50 \times 10^{-7}\ \text{m}^2} = 7.89 \times 10^{7}\ \text{Pa}$.

Step 3. Strain. $\dfrac{1.0 \times 10^{-3}\ \text{m}}{2.6\ \text{m}} = 3.85 \times 10^{-4}$.

Step 4. Modulus. $Y = \dfrac{7.89 \times 10^{7}\ \text{Pa}}{3.85 \times 10^{-4}} = 2.05 \times 10^{11}\ \text{Pa}$.