Using the data below and the SES forecast $a=0\mathrm{.}3,$ what is the forecast for the $3$rd week?

Week

Time Series Value

$1$

$17\mathrm{.}00$

$2$

$18\mathrm{.}00$

$3$

$25\mathrm{.}00$

$4$

$14\mathrm{.}00$

Answer format: Number: Round to: $1$ decimal places.