Suppose estimated quadratic model Yt = 500 + 20 t - t2 is the best-fitting trend of sales of XYZ Inc. using data for the past twenty years (t = 1, 2,.., 20). Which is incorrect? trend was higher in year 10 than year 20, Sales increasing by about 20 units per year, Latest year sales no better than in year 0, The turning point in period 10.