Interpolation problem. How can I generalize for a bigger number of intervals?

Imagine that I want to express in a way that I will describe below, a number that falls into a possible range of values.

E.g. the worse value is 30 and the best is 2.

So 16 would be expressed as: 1*w1 + 0*w2.

And 3 would be expressed as: 1*w1 + 0.93*w2.

What is a general code for this pattern?

What if I would want to include more intervals?

Is the following code correct?

function [w1 w2] = intrpolate(worse,best, given)
md = (worse+best)/2
if given >= md
    int = (given-md)/(best - md)
  w1 = 1 
  w2 = int
else
    int = abs((given-md))/(worse - md)
   w1 = int 
   w2 = 0
end
end

[Ameer Hamza]

The interpolation rule is not clear. What are the values of w1 and w2? Why is 16 expressed as 1*w1 + 0*w2? Same for 3 = 1*w1 + 0.93*w2???