The weekly sales data for a given product are given below for four weeks. Using $\backslash$alpha $=0\mathrm{.}7$ and $\backslash$beta $=$

$0\mathrm{.}6$ and initial values of S$1=125$ and T$1=18,$ answer the following questions. Show all work.

Week Sales

$1140$

$2156$

$3176$

$4201$

a$)$ Using exponential smoothing with trend, find the trend adjusted forecast $($TAF$)$ for week $5.$

b$)$ Calculate MAPE using data for weeks $2-4$