CSc 103 Programming Problem - Golf Pool Winner

The Atascadero country club has a golf "pool".  Each golfer pays $10 to participate in the pool.  At the end of the month, the person with the lowest average score wins the money in the pool.  To be eligible to win, a golfer must play at least three rounds of golf during the month. You have been hired to write a Java program to compute the monthly winner.

You are given a text data file that contains records of all golfers for the month.  Each record (line of the file) has three fields, separated by a semicolon.  The first field is the name of the person who completed a round of golf. The second field is the date on which they played.  The third field is the score earned on that round.

You are to write a program to read the data file and determine the golfer with the lowest average score (who has played at least three rounds).   If two golfers have the same average, the one who has played the most rounds is the winner.  (You may assume there will be no ties.) 
Also compute the number of rounds of golf played by the winning golfer.
The output (standard output) contains the golfer's name, average score (displayed with one decimal point), and number of rounds played.

The filename of the data file is provided to the program as a parameter on the command line.
Example command line:            java GolfPool jun2010scores.txt
If the program can't find a file with that name in the current directory, display a helpful error message.

Sample Input File

Dan Jones;5/14/2010;87
Sara Von Fleet;5/15/2010;73
Tim O'Hara;5/1/2010;93
Tim O'Hara;5/3/2010;89
Tim O'Hara;5/12/2010;91
Joe Bob Billings;5/18/2010;83
Sara Von Fleet;5/5/2010;75
Dan Jones;5/21/2010;85
Sara Von Fleet;5/8/2010;77

Sample Output

Winning golfer:  Sara Von Fleet
Average score:  86.5
Number of rounds: 3