EOM 3 task 3

I'm working on EOM 3 task 3 and currently struggling with what task 3 is asking us to do. We are given an expected fund rate of return of 6.5% and are told to estimate an effect if it increases or decreases by 2%. Not sure if i should just change the rate in the model to 8.5% or 4.5%. I've been looking at this for a good 1hr. Any explanations would be greatly appreciated. Thanks

EOM 3 task 3