Question

The following probabilities are based on data collected from U.S. adults. Individuals are placed into a weight category based on weight, height, gender and age.

underweight healthy weight overweight (not obese) obese
Probability 0.021 0.377 0.34 0.262
Based on this data, what is the probability that a randomly selected U.S. adult is not underweight?

Your answer should be given to 3 decimal places, and please show work~

Answer 1

The probability that a randomly selected U.S. adult is not underweight is 0.979

Explanation:

Probability Distribution

Four events were measured and their probabilities computed as follow

`\left|\begin{array}cUnderweight&Healthy&Overweight&Obese\\0.021&0.377&0.34&0.262\end{array}\right|`

Please note the sum of the probabilities is 1, thus the distribution is correctly expressed. We want to compute the probability that a randomly selected U.S. adult is not underweight.

Knowing the adult doesn't belong to the underweight category, then they must belong to any of the other categories, thus the probability is the sum of their individual probabilities or (easily computed), the total probability minus the underweight probability:

`P(NOT\ underweight)=1-P(underweight)`

`P(NOT\ underweight)=1-0.021=0.979`

The probability that a randomly selected U.S. adult is not underweight is 0.979