I have the following formula from my text book:

https://i.imgur.com/BZZkRzL.jpg

So for my example, I have the following:

Base value input: 110

Increased input by 10%: 121

Output before the 10% increase: 520

Output after the 10% increase: 578

So when calculating the sensitivity coefficient as mentioned in my text book, is this correct?

Basically, what I'm confused about are the denominators in the fraction. The "input" and "output" that you have to divide by. Am I supposed to use the values before the sensitivity analysis like I've done? Or should I use the values after the sensitivity analysis instead (so dividing the difference with 578 for output and 121 for input)?

Thank you!!