Answer
The probability that a randomly picked American has not done 4 years of high school is $\frac{1}{6}$.
Work Step by Step
We know that the probability that a randomly picked American has not done 4 years of high school can be computed by putting the values from the table in the formula as given below:
$\begin{align}
& P\left( \text{has not completed 4 years of high school} \right)=\frac{29}{174} \\
& =\frac{1}{6}
\end{align}$
Thus, the probability that a randomly picked American has not done 4 years of high school is $\frac{1}{6}$.
