Q = 960 - 1.2P + 1.4Y + .003A where, Q and P are the quantity and price of the product respectively, Y is the income, and A is the advertising expenditures. ALl the variables are in the natural logarithmic form and are estimted coeficcients are statistcally significant. The average annual sale and the average price of product are 60000 units and $8000 respectively. Price elasticity demand is? Income elasticity of demand is? Advertising elasticity of demand is? The optimum level of advertising spending for the firm is?