640: Mainline

Now suppose that you decide you want two versions of analyze_trades:

• You want one version, the verbose version, to display two complete sentences.
• You want another version, the concise version, to display just two numbers, the mean price per share and the mean number of shares traded.

The verbose version is to display a report such as the following:

The mean price per share of the trades is 10.00. 
The mean number of shares traded is 600. 

The concise version is to display a shorter report, or perhaps write a shorter report into a file to be read by another program:

10.00 600