Nelson Industries manufactures a part for a type of aircraft engine that is becoming obsolete. The sales history for the last 10 years is as follows: Year 11 Dec- Dec- Dec- Dec- Dec- Dec- Dec- Dec- Dec- Dec- 08 09 10 12 13 14 15 16 17 Sales 945 875 760 690 545 420 305 285 250 210 Use the above table to estimate a regression model for a linear time trend of sales, and answer the following questions. What is the mean absolute percent error of the linear regression estimates for these 10 years?