The following time series shows the prices of a particular product over the past $18$ months:

Month Price

$1450$

$2300$

$3440$

$4360$

$5290$

$6450$

$7340$

$8370$

$9500$

$10490$

$11430$

$12390$

$13350$

$14385$

$15410$

$16400$

$17330$

$18480$

$1.$ Construct three time series plots $($for linear, power, and exponential$).$

$2.$ Use Excel$$s Trendline tool to develop the equations for the linear, power, and

exponential trend component.

$3.$ Calculate APE and MAPE for each based on $18$ months of data