Problem $18-3($Algo$)$

Given the following history, use a three$-$quarter moving average to forecast the demand for the third quarter of this year. Note, the $1$st quarter is Jan, Feb, and Mar; $2$nd quarter Apr, May, Jun; $3$rd quarter Jul, Aug, Sep; and $4$th quarter Oct, Nov, Dec.

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Last year $135155165195205235180170160235260285$

This year $155165170225215240$