Calculate the forecast for the $7$th month, using exponential smoothing method, with a smoothing constant of $0\mathrm{.}3.(19)$ Under the Exponential Smoothing Method, the forecast for the $5$th month is $($a$)4489\mathrm{.}34($ b$)4532\mathrm{.}54($c$)4473\mathrm{.}21($d $)4554\mathrm{.}35()$ none of the above $(20)$ Under the Exponential Smoothing Method, the forecast for the $6$ month is $($ a$)4478\mathrm{.}32($ b$)4448\mathrm{.}25()4564\mathrm{.}29($d$)4572\mathrm{.}28($ e$)$ none of the above $(21)$ Under the Exponential Smoothing Method, the forecast for the $7$th month is: $($ a$)4472\mathrm{.}77($ b$)4521\mathrm{.}34()4473\mathrm{.}16($d$)4574\mathrm{.}18($e$)$ none of the above