Could you help with this problem? Step by step instructions would be helpful. For the base case in this section, as a percentage of sales, COGS = 70%, SGA = 15 %, R&D is 2.4% Depreciation, interest expense are xed as stated, tax is 20%. Given the following case, calculate the independent effects of a 1% increase in Gross Margin, a 1% decrease in Tax Rate and a 5% increase in Sales. base cost 1% increase in Grose Margin 1% Decrease in Tax Rate 5% Increase in Sales _ 51 Total Costs & Expenses 2005 Operating Income 105 Interest Expense 39 Earnings Before Taxes 66 3 Net Income 53