A forecasting method used to predict can opener sales applies the following set if weights to the last five periods of data:$0\mathrm{.}1,0\mathrm{.}1,0\mathrm{.}2,0\mathrm{.}2,0\mathrm{.}4($with $0\mathrm{.}4$ being applied to the most recent observation$).$ Below are the observed values of can opener sales. Determine the following: the one step ahead forecast for period $9$