What is a BMI and How do you Calculate it?

SOLVED:The body mass index (BMI) measures body weight in relation to height. A BMI of 25 to 29.9 is considered overweight, a BMI of 30 or more is considered obese, and a BMI of 40 or more is morbidly obese. The percentage of the U.S. population that is obese is approximated by the function P(t)=0.0004 t^3 0.0036 t^2 0.8 t 12 (0 ≤t ≤20) where t is measured in years, with t=0 corresponding to the beginning of 1991 . a. What percentage of the U.S. population was deemed obese at the beginning of 1