I have the basic format to figure out cost per lot for the question below but I do not see how in my book relative sales price is calculated. The best I could come up with is that total sales price is multiplied by .0001

Relative Sales Value Method

Group # of lots price per lot
1 9 $3,000
2 15 $4,000
3 17 $2,400

Operating expenses for the year allocated to this project are $18,200. Lots unsold at year end were as follows:

Group1 5 lots
Group 2 7 lots
Group 3 2 lots

At fiscal year end what is net income?

I have: lots, number of lots,price per lot,total sale price but I don't see how to calculate relative sale price?