Allocate a percentage of score based on rank

Hello - I'm trying to figure out how to allocate a percentage of a total score based on a ranked list of items.

There is a ranked list of items and the item that is ranked 1 - should receive the highest percentage of the total available points and the remaining items on the list should receive a % of the remaining value based on their rank on this list.

For example, there is a list of 5, ranked 1 - 5, 1 being the best.
The total score for the category is 20 (a variable). The max score that the highest ranked item can get is 50% (a variable) of the total available (10 in this case) and the remaining score (10) should be allocated to the remaining items in the list based on their ranking - 2- next highest, 3-next and so on until item ranked 5 receives the lowest score.

is that possible? Thanks!

Hi - thanks for the quick reply! I guess that's what I'm trying to figure out, if it's even possible.

I'd like for the top number in the rank to receive some percentage of the total available score (entered as a variable) and then the remaining score be allocated by a percentage based on the number of items in the rank order list and the rank (1 is highest and n is lowest) to determine the % allocation of the remaining items. Here are two examples...

Avail Points: 20
Max Points: 10.00 - top score (50%)

Example 1, 7 items in the list
Rank Points
1.00 10.00
2.00 5.00
3.00 2.50
4.00 1.25
5.00 0.75
6.00 0.25
7.00 0.25

Example 2, 5 items in the list
Rank Points
1.00 10.00
2.00 5.25
3.00 2.5
4.00 1.5
5.00 0.75

Ok -this is helpful, thanks! As a general rule the next rank should receive some % of the previous (next highest) rank until the total number of points are allocated down the list, depending on how many items in the list. If we could set the allocation percentage as part of the formula, that would be perfect.

So, for example:

There are 7 items in the list
The Total score available for the list is 20
The Max score the highest ranked item can get is 50% of the max (10)
Each subsequent items receives up to 50% (another variable) of the remaining score until the total is allocated

Is something like that possible?

Basically, i'm trying to figure out a way to do a simple rank of a list from most to least important and then based on that ranking allocate some number of total possible points, based on a % of what's available. Maybe there is a different approach that is easier?

Nice one! Goal Seek works nicely and shg's formula works nicely as well. Problem solved! Thanks!!