My math homework

Question

matt completed his first race in 15.163seconds timer was 15.24 seconds which is the following shows the correct relationship between 15.163 and 15.24

Answer 1

true time: 15.163

timer: 15.25

off by .087 part of a second

.087/15.163

= 0.573765 % off

about 1/2 a percent off, roughly

error may be the timer's human reflexes more than a mis-calibrated watch