The demand for a firm’s product is presented as Qd = 28 – 4p.
            Prices over the period are $2.50; $3.50; $4.50; $5.50 and $7.00.

            Calculate:

1. the quantity demanded at each price;
2. the total revenue at each price;
3. (i)         what is the coefficient of price elasticity of demand

when price increased from $2.50 to $3.50?               
            (ii)        is the demand elastic or inelastic ?