A simple question but I'll ask anyway, I am writing a report about speed improvements on a particular server task. Originally the task took 4 minutes (240 seconds), it now takes just 10 seconds. How can this be represented as a percentage? I think what I'd like it to say is "this shows a X% improvement, you spent your money wisely". I assume this is possible? I came up with either 230% (doesn't seem right) or 958% (also doesn't seem right).
Quick note: I couldn't find a tag which this falls under (percentage or algebra) so I've stuck it under homework, maybe someone more experienced on here can amend that for me.
$$\frac{10}{240}\times100=4.1\dot6$$ Now if ten is $4.1\dot6$% then thats a $100 - 4.1\dot6$% improvement.