Required information (The following information applies to the questions displayed below.) Phillips Company manufactures air-conditioning units for commercial buildings and has noticed considerable variation in shipping expenses from month to month as per the data below: Month January February March April May June July Units Shipped 4 4 5 2 3 6 8 Total Shipping Expense $2,000 $ 2,900 $ 2,350 $ 1,260 $ 2,040 $ 2,700 $ 3,840 4. What is the cost formula for shipping expenses? $ 400 + $ 430 X