The winner is the offer that returns the most revenue per visitor.

Example: Offer A gets 1000 visitors and 25 buyers at $100 each. Offer B gets 900 visitors and 60 buyers at $30 each. Offer A is the winner because $2.50 per visitor is more than $2.00 per visitor.

Obviously, I want to end the test as quickly as possible, declare the winner, and move on to the next test. But how do I calculate my confidence level that the leader is the winner?

If possible, express your solution in terms of Excel's statistical functions.

Thanks.

Charley