i need help with the last two , i keep getting the same answer

Problem A-4 The Economists' Approach to Pricing [LOA-1] The postal service of St. Vincent, an island in the West Indies, obtains a significant portion of its revenues from sales of special souvenir sheets to stamp collectors. The souvenir sheets usually contain several high-value St. Vincent stamps depicting a common theme, such as the life of Princess Diana. The souvenir sheets are designed and printed for the postal service by Imperial Printing, a stamp agency service company in the United Kingdom. The souvenir sheets cost the postal service $1.00 each. St. Vincent has been selling these souvenir sheets for $7.00 each and ordinarily sells about 58,000 units. To test the market, the postal service recently priced a new souvenir sheet at $8.00 and sales dropped to 48,000 units. Required: 1a. Calculate the contribution margin for sale price of $7.00 each or $8.00 each? $7.00 Price $8.00 Price Unit sales Sales Cost of goods sold Contribution margin 2. Estimate the price elasticity of demand for the souvenir sheets. (Negative amount should be indicated by a minus sign. Do not round intermediate calculations. Round your answer to 4 decimal places.) Answer is complete but not entirely correct. Price elasticity of demand (1.2069) 3. Estimate the profit-maximizing price for souvenir sheets. (Do not round intermediate calculations. Round your answer to 2 decimal places.) Answer is complete but not entirely correct. Profit-maximizing $ 7.79 price