17/42 as a percentage is 40.48%. This number tells you how much of a whole the fraction represents when you look at it on a scale of 100.
The fraction 17/42 is a bit less than one half, so its percentage is also a bit under 50%. When you see 40.48% on a chart or a report, you know it comes from that same fraction.
If you need to compare it to other fractions, just remember that 40.48% is the same as 0.4048 in decimal form. That makes it easy to use in calculations or to estimate sizes.
In everyday situations, saying something is 40.48% complete is a clear, concise way to describe progress that’s a little less than halfway done.