Maths question

If the power on hours is 4424, and the lifetime use is 13% how do I work out the expected lifetime hours?

Assuming I am reading the question right then divide 4424 by 13 and then multiply by 100. Would give 34,030 hours as the result.

This is assuming that the 13% is that it believe you have used 13% of the total expected lifetime.

3.88 years which sounds about right for an SSD.

In that case my old one should be at the end of it's life and yet according to SSD life it still have 5 years to go.

They are Mean Time Between Failure figures usually so some may fail quickly and others may go on for much much longer. With SSDs it will also depend a lot on how much reading and writing there is - they shift bits around and turn off duff areas so until it has done enough that the duff areas get too high it will just keep working.

An SSD that is on but doing little should last a very long time.