1. The problem statement, all variables and given/known data A child weighs 34 Kg is seated on a seesaw. While a child who weighs 40 kg is situated on the opposite end of the seesaw. The function B(x)= 34x / 40 gives the distance that the 40 kg child must sit from the center of the seesaw when the 34 kg child sits x meters from the center. The seesaw is 9m long find the average rate of change in distance as the lighter childs distance changes from 1.5m to 2.5meters. 2. Relevant equations I used the quotient rule to find the derivative of the function. Which turns out to be 68 / 80. 3. The attempt at a solution The thing is the derivative is 34/40. Which equals to 0.85. The prof gave us the answer which is -1.275. I havent come close to that. I used... f(x) = f(b) - f(a) / b-a I dont know how to tackle the average rate of change.