Hi
I have an array in which i need to interpolate(linear).

For ex,

5 6 7 8
2 60 70 80 90
3 50 60 70 80
4 40 50 60 70
5 30 40 50 60

The first row (Xvalues) and the first column (Yvalues):
For ex, for X=5.5 and Y=2.5, my interpolated values should be 60. How
can i write a formula for this? I would greatly appreciate any help in
this.
Thanks so much
GP