Q$15$

Below you are given the first two values of a time series. You are also given the first two values of the exponential smoothing forecast.

If the smoothing constant equals $.2,$ then the exponential smoothing forecast for time period $3$ is

a$.$

b$.$

c$.$

d$.$

$\backslash$table$[[18],[18\mathrm{.}8],[21\mathrm{.}2],[40]]$