We know Christine's second throw was 30 feet high because 20 + 10 = <<20+10=30>>30.
We know Christine's third throw was 34 feet because 30 + 4 = <<30+4=34>>34.
Janice's first throw was 16 feet because 20 - 4 = <<20-4=16>>16.
Janice's second throw was 32 feet because 16 * 2 = <<16*2=32>>32.
Janice's final throw was 37 feet high because 20 + 17 = <<20+17=37>>37.
The six throws were 20 feet, 30 feet, 34 feet, 16 feet, 32 feet, and 37 feet, and of these numbers, 37 feet was the highest.
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