Can you please explain how we came up with this answer? Thanks in advance

The fictional company Ad Otum Inc is going public and uses an auction to determine the price to set in the IPO. They have received the following bids Price ($) Number of Shares 14.40 100 000 14.20 150 000 14.00 420 000 13.80 680 000 13.60 860 000 13.40 725 000 13.20 380 000 a. What will the winning auction price be if Ad Otum Inc wants to sell 2 million shares in the IPO? Answer in dollars with two decimals (i.e. 18.00, not 18). $ 13.60 b. What would the winning auction price be if Ad Otum Inc instead wanted to sell 3 million shares in the IPO? Answer in dollars with two decimals (i.e. 18.00, not 18). $ 13.20