Answer:
1/2
Explanation:
Based on the information observed from the attached box and whisker plot, the Fraction of dunk tanks which requires atleast 500 gallons of water. This fractional value will be the property of plot in the position marked as 500 on the plot. The point which refers to 500 gallons on the plot is the ticked point in between the box. This point represents the median value in a box and whisker plot.
The median value represents the 50th percentile value which relates to half of the distribution. This means that fraction of dunk which requires atleast 500 gallons is : (50/100) = 1/2