Since you know that the equation of straight line is y=Mx + c Where m mean gradient , and c means intercept We don’t know our intercept neither do we know our gradient So we have to find these to get our equation Therefore, to find m( gradient) from the table We are going to use the formulae for gradient which is M=y2-y1 / x2-x1 I.e from the table M= 23-15 / 4-2 M=8/2 M=4 Therefore how gradient is 4