Using forward divided difference the true error in the calcu

Using forward divided difference, the true error in the calculation of a derivative of a function is 32.0 for a step size of 0.4. If the step size is reduced to 0.11, the true error will be approximately?

Solution

True error = 32.0 when step size is 0.4

step size is reduced by 0.4/0.11 = 3.63

Therefore true error is reduced by 32.0/3.63 = 8.81