Answer:
218.7 lb.
Step-by-step explanation:
We have been given that the weight of male american between the ages 18 to 25 is normally distributed, with mean of 162.7 lb and a standard deviation of 28 lb.
One definition of obesity states that a person is obese if the z-score of his or her weight is greater than 2.
We will use z-score formula to solve our given problem.
, where,
,
,
,
.
Upon substituting our given values in z-score formula we will get,

Now let us solve for x.
Upon multiplying both sides of our equation by 28 we will get,


Let us add 162.7 to both sides of our equation.


Therefore, the obesity threshold weight for a young adult American male is 218.7 pounds.