National Scan, Inc., sells radio frequency inventory tags. Monthly sales for a seven$-$month period were as follows:

Month Sales

$(000)$Units

Feb. $16$

Mar. $18$

Apr. $13$

May. $20$

Jun. $22$

Jul. $23$

Aug. $28$

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a$.$ Forecast September sales volume using each of the following:

$(1)$ The naive approach.

$(2)$ A five$-$month moving average. $($Round your answer to $2$ decimal places.$)$

$(3)$ A weighted average using $0\mathrm{.}75$ for August, $0\mathrm{.}15$ for July, and $0\mathrm{.}10$ for June. $($Round your answer to $2$ decimal places.$)$

$(4)$ Exponential smoothing with a smoothing constant equal to $0\mathrm{.}30,$ assuming a March forecast of $18(000).($Round your intermediate forecast values and final answer to $2$ decimal places.$)$

$(5)$ A linear trend equation. $($Round your intermediate calculations and final answer to $2$ decimal places.$)$