Problem
The following table represents the highest educational attainment of all adult residents in a certain town. If a resident who has completed just high school or only some college is chosen at random, what is the probability that they are aged 30-39? Round your answer to the nearest thousandth. \begin{tabular}{|c|c|c|c|c|c|} \hline & Age 20-29 & Age 30-39 & Age 40-49 & Age 50 \& over & Total \\ \hline High school only & 681 & 483 & 536 & 1426 & 3126 \\ \hline Some college & 2106 & 1120 & 578 & 1465 & 5269 \\ \hline Bachelor's degree & 1532 & 1642 & 928 & 1674 & 5776 \\ \hline Master's degree & 1082 & 615 & 431 & 1001 & 3129 \\ \hline Total & 5401 & 3860 & 2473 & 5566 & $\mathbf{1 7 3 0 0}$ \\ \hline \end{tabular} Answer:
Solution
Step 1 ：Find the total number of residents who have completed just high school or only some college: \(3126 + 5269 = 8395\)
Step 2 ：Find the number of residents aged 30-39 who have completed just high school or only some college: \(483 + 1120 = 1603\)
Step 3 ：Calculate the probability: \(\frac{1603}{8395} = 0.190946992257296\)
Step 4 ：Round the probability to the nearest thousandth: \(\boxed{0.191}\)
