Consider the time series below. Complete parts a and b below.

Period

$1$

$2$

$3$

$4$

$5$

$6$

$7$

$8$

Demand

$13$

$24$

$27$

$33$

$20$

$22$

$26$

$15$

Question content area bottom

Part $1$

$$a$)$

Forecast the demand for Period $9$ using exponential smoothing with trend adjustment. Set alphaequals$0\mathrm{.}2$ and betaequals$0\mathrm{.}6.$