A contrast budget can compare two finite waits without fitting an exponential. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

The first finite wait retains three fourths

With the first declared wait, 60 of 80 shots remain, so the retained fraction is 3/4.

ffirst=34f_{\text{first}}=\frac{3}{4}
First finite waitThe retained fraction is checked.3/4retained1/4lostsurvival budget

The longer declared wait retains one half

The contrast budget keeps 40 of 80 shots, so the fraction is 1/2.

fcontrast=12f_{\text{contrast}}=\frac{1}{2}
Contrast finite waitThe budget is a declared finite count model.1/2retained1/2lostsurvival budget