An infant's pulse rate is measured to be 121 ± 3 beats per minute. what is the percent uncertainty in this measurement?

The infant's pulse rate is 121 ± 3 beats per minute, so the uncertainty of the measurement would be 3 beat per minute. To change it into percent uncertainty, you need to divide it with the measure value of the pulse rate. The calculation would be: 3 beat per minute/121 beat per minute = 2.48%