I cannot understand how to calculate the supporting schedules (1-9)

Please correct my numbers.

$ Budget Assumptions First Month's Sales in Units Unit Sales Growth Per Month Unit Sales Price 120,000 250 12.00 LEFT/FIND Functions First Month's Sales in Units Assumption Unit Sales Growth Per Month Assumption Unit Sales Price Assumption Gross Margin Commission Ending Inventory 50% 10% 60% TRIM Function Gross Margin Commission Ending Inventory $ Minimum Cash Balance Assumption Interest Rate Assumption 20,000 12% SUBSTITUTE Function Minimum Cash Balance Assumption Interest Rate Assumption Month month1 month2 month3 Collections 25% 50% 25% Payments 60% 40% 0% CONCATENATE/RIGHT Function Period 1 Period 2 Period 3 UPPER Function PERIOD 1 PERIOD 2 PERIOD 3 LOWER Function period 1 period 2 period 3 Operating Expenses Payroll Utilities Other Per Month 16,000 7,000 19,500 MID Function 7200 Payroll 7500 Utilities 7900. Other B E F G J 1 Wally's Widgets 2 Budgeted Sales in Units 3 Add: Ending Inventory 4 Total Needs 5 Less Beginning Inventory 6 Required Purchases in Units 7 Required Purchases in Dollars 8 Budgeted Sales in Dollars 9 Sales Commissions in Dollars January February March April May 120000 120250 120500 120750 72150 72300 72450 72600 192150 192550 192950 193350 72000 72150 72300 72450 10150 10400 10650 10900 $ 60,900 $ 62,400 $ 63,900 $ 65,400 $ 10000 10021 10042 10063 1000 1002 1004 1006 June July 121000 121250 72750 72900 193750 194150 72600 72750 11150 11400 66,900 $ 68,400 $ 10083 10104 1008 1010 H 1 K M August September October November December 121500 121750 122000 122250 122500 122750 73050 73200 73350 73500 73650 73650 194550 194950 195350 195750 196150 196400 72900 73050 73200 73350 73500 73650 11650 11900 12150 12400 12650 12750 69,900 $ 71,400 $ 72,900 $ 74,400 $ 75,900 $ 76,500 10125 10146 10167 10188 10208 10229 1013 1015 1017 1019 1021 1023