Simply get the value of 72 percent out of 138 pounds.
138 * 72% = 9926 / 100% = 99.36 lbs
We need to divide the answer by 100% if 72% is not converted into decimal to ensure that we get the exact value in pounds.
or
138 * 72%/100% = 138 * 0.72 = 99.36 lbs
If in the event that 99.36 lbs and 72% is given, we can find the weight of the person by dividing the value by its corresponding percentage.
99.36lbs / (72%/100%) = 99.36 / 0.72 = 138 lbs
If both values are given and percentage is missing, then divide the part by the whole to get the percentage.
99.36 lbs / 138 lbs = 0.72 * 100 % = 72%