Use the call options with strike price of $10, $15 and $20 to draw the profit diagram of the "Long Butterfly" strategy on expiration date.

Definition of a "Long Butterfly" strategy: Long ONE low strike price call option, long ONE high strike price call option and short TWO units of middle strike price call option.

(1) Find the payoff and profit for buying one low strike call.

(2) Find the payoff and profit for selling one middle strike call.

(3) Find the payoff and profit for for buying one high strike call.

(4) Find the profit for the long butterfly strategy.

(5) Make a smooth marked scatter chart in which the strategy profit is the y-axis and the stock price on expiration date is the x-axis.

Low Strike Call - Strike Price: 10 Option Price: 7.3

Middle Strike Call - Strike Price: 15 Option Price: 2.71

High Strike Call - Strike Price: 20 Option Price: 0.04