To determine the upper quartile (Q3) of the number of museum visitors from a box plot, you would typically look at the value that separates the highest 25% of the data from the rest. In a box plot, the upper quartile is represented by the line that marks the edge of the box on the right.
Since the actual box plot image is not provided, I can't see the specific values. However, if you can share the values indicated on the box plot or provide more descriptions about the data points, I can help you find the upper quartile. Please provide the necessary details or values!