needing help understanding how 156,190 was figured for the answer:)

Brian Partners makes attic vents. Their production budget is shown below: Jan production, units 20,000 Feb production, units 36,000 Mar production, units 40,000 Each vent requires 4.7 feet of metal sheeting. Management wants enough sheetingto meet 9% of next month's production needs. Sheeting costs $1.55 T per foot. What is the material budget for sheeting for January (in dollars)? Enter as a whole number, no commas and no dollar signs. Answer: 156,190