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Old Faithful Eruptions


The following graph is a cumulative relative frequency distribution. The data shows the duration (in minutes) of several eruptions of the Old Faithful geyser in Yellowstone National Park. Cumulative relative frequencies are equivalent to percentiles.

For instance, the point (2, 0.2) means that 20% of all eruptions recorded lasted 2 minutes or less.

Part 1:
Estimate what proportion of eruptions last 3 minutes or less.

Part 2:
Estimate the median duration of an eruption.

Part 3:
Estimate what proportion of eruptions last 5 minutes or more.