Question: $18\mathrm{.}3$

Problem:

A department store may find that in a four month period the best forecast is derived by using

$25\%$

of actual sales for the most recent month, $30\%$

of two months ago,

$15\%$ of $3$ months ago and $30\%$ of $4$ months ago. The actual sales were:

Month

What is the Forecast for Month $5$