a)Using appropriate graphs explain what causes a change in demand and a change in quantity demanded.

b)Price of oranges in Adelaide market increased from $3.00 to $4.00 per kg. As a result, the quantity demanded for oranges decreased from 350 kg to 300 kg per day. Using the midpoint formula:

i)Calculate the price elasticity of demand (E_d) for oranges.

ii)Is the demand for oranges elastic or inelastic or unitary elastic? Why?

iii)Interpret the E_d coefficient of oranges. In your interpretation, please mention in percentage points by how much the quantity demanded has changed (%DQ) as a result of the change in price (%DP).

iv)Will the above change in price cause total revenue to increase, decrease or remain unchanged? Show how you worked it out?