A biologist estimates that the human body contains 90 pounds of water for every 100 pounds of body weight. At the rate estimate the number of pounds of water in a child who weighs 80 pounds

72 lb

Step-by-step explanation:

Write and solve an equation of ratios:

80 pounds             x

=

100 pounds      90 pounds

Cross multiplying, we get (100 pounds)x = 7200, or x = 72 pounds.

The 80 pound child's weight includes 72 pounds of water.

the answer is 31.27mph