Answer:
The price elasticity of supply is <u>0.83</u> and the supply is price <u>inelastic</u>.
Explanation:
The price elasticity of supply is the ration of the percentage change in the quantity of a product supplied to the percentage change in price. It is used to measure essentially the degree to which the quantity of a good or service supplied change with a change in price. Mathematically, Price elasticity of supply (PES) is:
PES = (% change in the quantity ) ÷ (% change in price)
% change in quantity =
% change in price = 
where :
Q₂ = New quantity supplied = 400 cups of coffee
Q₁ = Initial quantity supplied = 300 cups of coffee
P₂ = new price = $7
P₁ = initial price = $5
∴ % change in quantity = 
% change in price =
∴ PES = 
Finally, the following rules hold for PES:
PES < 1 = inelastic
PES > 1 = elastic
PES = 1 = unitary
PES = 0 = perfectly inelastic
PES = ∞ = perfectly elastic
Hence since our answer is 0.83, the PES is inelastic for a cup of coffee, meaning that the degree of price change is of a more greater proportion that the change in quantity supplied.