Economics 20th Edition by Campbell McConnell ,Stanley Brue ,Sean Flynn

Exercise 1

at the demand curve in Figure 4.2a. Use the midpoint formula and points a and b to calculate the elasticity of demand for that range of the demand curve. Do the same for the demand curves in Figures 4.2b and 4.2c using, respectively, points c and d for Figure 4.2b and points e and f for Figure 4.2c.
Reference Figure 4.2a, Figure 4.2b, Figure 4.2c