E3. [28 points] Petra's company makes fancy chocolates. She does not sell her chocolates in stores, only online. Customers pay a at shipping fee of $25, regardless of how many chocolates they buy. Each bar of chocolate is priced at $3. Assume downward sloping Marginal Willingness to Pay (MWTP) for chocolate bars for all consumers. Consumers can dier in their MWTP for a given quantity. The shipping fee is NOT what Canada Post charges, but just another way for Petra to earn revenues. a) [9 points] Claim: If Petra lowers her shipping fee to a $20 at fee, she will sell more chocolate bars. Agree, Disagree or It depends? Explain your reasoning. A diagram is not an explanation. Your explanation needs to be sufcient without a diagram. Solution: For consumers who were buying chocolate already, their quantity is determined by marginal cost which in this case is $3. As that does not change, the quantity bought by existing customers does not change. However, the lower shipping cost may bring new customers. For these customers the quantity they would buy at $3 will result in a total benet