Answer: The proportion of oil tankers that had spills is [tex]\dfrac{156}{474}[/tex] or 0.329.
Step-by-step explanation:
Since we have given that
Number of tankers is drawn = 474
Number of tankers did not have spills = 318
Number of tankers have spills = 474 - 318 = 156
Proportion of oil tankers that had spills is given by
[tex]\dfrac{Containing\ spill}{Total}=\dfrac{156}{474}=0.329[/tex]
Hence, the proportion of oil tankers that had spills is [tex]\dfrac{156}{474}[/tex] or 0.329.