Using the data below, what is the weighted moving average forecast for the $4$tr week?

The weights are $\mathrm{.}20,\mathrm{.}30,\mathrm{.}50($oldest period to most recent period$)$

$\backslash$table$[[$Week$,$Time Series Value$],[1,6\mathrm{.}01],[2,16\mathrm{.}13],[3,11\mathrm{.}19],[4,5\mathrm{.}31]]$

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