Using the data below, what is the simple exponential smoothing forecast for the $4$ th week where $=0\mathrm{.}4?$

Week

$1$

$2$

$3$

$4$

Time Series Value

$6\mathrm{.}00$

$4\mathrm{.}00$

$7\mathrm{.}00$

$5\mathrm{.}00$

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