If you want to describe a population with more than two categories,which test(s)can you use?

How much is $900 after a decrease of 90%?

The Lightning laser printer prints 30% more pages per minute than the Reliable laser printer. What percentage less time than the Reliable will the Lightning require for long print jobs?

Duncan retired recently and plans to utilize other savings for a few years while his RRSP continues to grow on a tax-deferred basis. The RRSP is currently worth $142,470. How long will it be until the amount in the RRSP is large enough to purchase a 25-year annuity paying $1700 at the end of each month? Assume that the RRSP and the annuity will earn 8.75% compounded semi-annually.