Some purchasing specialist jobs also assign specialists to track the maintenance of office equipment. Maintaining records of warranties and service agreements is sometimes expected of a person in this position.
A retail price index would take this into account and use a weighted average which gives more prominence to commonly bought items. Excel does not contain a built in function to calculate a weighted average. It is however easy to do it using the SUMPRODUCT() function in a simple formula. SumProduct() multiplies two arrays (or ranges) together and returns the sum of the product. In the illustration it would calculate '(B4 x C4) + (B5 x C5) + (B6 x C6)'.
Divide equation 1 by equation 2. m 1 v 1i 2 âv 1f (2) m 1 (v 1i âv 1f) = m 2 v 2f 2 âv 2i (2) m 2 (v 2f âv 2i) After all the cancellations, we are left with: v 1i +v 1f = v 2f +v 2i eqn. 3 Solving for v 1f we get: v 1f = v 2f +v 2i âv 1i eqn. 4 Now we take equation 4 and substitute back into one of our original equations to solve for v 2f. Since the momentum equation is easier, lets use that.