please help. thank you!

Here are the data for the past 21 months for actual sales of a particular product: Develop a forecast for the fourth quarter using a three-quarter, yeighted moving averoge. Weight the most recent quarter 0.50 , the second most recent 0.25 , and the third 0.25 . Do the problem ush quarters, as opposed to forecasting separate months. (Round your answer to 2 decimal places.)