Sometimes curvature in a scatterplot can be fit adequately (especially to the naked eye) by several trendlines. We discussed the exponential trendline, and the power trendline is discussed in the previous problem. Still another fairly simple trendline is the parabola, a polynomial of order 2 (also called a quadratic). For the demand-price data in the file P16_10.xlsx, fit all three of these types of trendlines to the data, and calculate the MAPE for each.

Which provides the best fit? (Hint: Note that a polynomial of order 2 is still another of Excel’s Trendline options.)