A titanium bar 8.75 mm in diameter will stretch from a 150 mm length to a 150.5 mm length when a force of 23 kN is exerted. Calculate the modulus of elasticity of the alloy.

My lecture teacher has not provided a formula regarding how to calculate the modulus of elasticity, apart from a strain formula. I've tried individually to work it out and its my final question. Very much appreciated if i can get a response.