Cumulatively sum numbers in an array between two indices

Hi,

Lets say I have an array with 10 positions as in the picture, for example.

I want to add all the numbers between Index 4 and index 8, and get my answer of 150

What would be the best way of going about this?

Thanks

Answer 1

[DGM]

Something like this:

x=5:5:50
sum(x(4:8))

[TOK]

Perfect, thank you very much. I knew it was something quite simple but I just couldn't find or work it out!