11. Incorrect. The answer is true not false. In the oil sample set, the engineer has six samples which satisfy the condition: 31, 32, 33, 34, and 35. The sampling process is without replacement, so the probability that the first element is light oil is 5/15. The second element will be light oil with a probability of 4/14. Finally, the third element will be light oil with a probability of 3/13. Accordingly, the probability that the three elements are light oil is the product of three probabilities: (5/15) (4/14) (3/13) ≈ 0.0220 or 2.20%. In set notation, we have that P₁(light oil) ∩ P₂(light oil) ∩ P₃(light oil) ≈ 2.20%, where the subscript represents the number of the draw.