5. The accompanying table shows the price and yearly quantity sold of souvenir T-shirts in the town of Crystal Lake according to the average income of the tourists visiting.
| Price of T-shirt | Quantity of T-shirts demanded when average tourist income is $20,000 |
Quantity of T-shirts demanded when average tourist income is $30,000 |
| $4 | 3,000 | 5,000 |
| 5 | 2,400 | 4,200 |
| 6 | 1,600 | 3,000 |
| 7 | 800 | 1,800 |
Using the midpoint method, calculate the price elasticity of demand when the price of a T-shirt rises from $5 to $6 and the average tourist income is $20,000. Also calculate it when the average tourist income is $30,000.
Using the midpoint method, calculate the income elasticity of demand when the price of a T-shirt is $4 and the average tourist income increases from $20,000 to $30,000. Also calculate it when the price is $7.