You own a factory that sells three products:

• A colorful shell that can be snapped on an iPhone to make it look pretty, but doesn't add much protection (these sell for$10).
• A hard cover that is somewhat ugly, but provides protection for the iPhone's screen (these sell for$8).
• A combined colorful protector obtained by snapping the previous two components to each other. These make the phone look pretty and provide protection, and retail for$15
• .The process of snapping the two components to each other doesn't require any special tools, and can happen right before the sale.

You are about to offer your products for sale at a Business School networking event, and the demand for each of these products at the event is normally distributed, with the following parameters (mean, standard deviation):

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