# Weighting things relative to a number

I have a collection of data that has the following structure:

[Customer: 1, OrderCount:11 ],
[Customer: 2, OrderCount:22 ],
[Customer: 3, OrderCount:1 ]
...


I need to add another property called "Weighted". This property has a maximum value of 15 and a minimum value of 5. I need to figure out a formula that allows me to calculate this property value in relation to OrderCount across the entire collection of data. In the context of the data collection above, the result would be:

[Customer: 1, OrderCount:11, Weighted:10],
[Customer: 2, OrderCount:22, Weighted:15],
[Customer: 3, OrderCount:1, Weighted:5]


What does this formula look like? I can't seem to crack this nut. Thank you for your help!

-
Why does weighted = 10 for Customer 1, and why 15 for Customer 2 and why 5 for Customer 3? – oks Feb 9 '13 at 15:13
@BillJones: I would have thought you would have made weighted = $\large \frac{\text{OrderCount}}{\text{Total-Number-of-Orders}}$ for each Customer, so you know the weight of the each's purchases. Regards – Amzoti Feb 9 '13 at 17:01