Percentiles and quartiles are closely related. The lower quartile is actually the 25th percentile, the median is the 50th percentile and the upper quartile is the 75th percentile. The xth percentile is the value below which x% of the data values lie.
We can find percentile from cumulative frequency curves in the same way as we would find the quartiles and median/.
To find the 95th percentile go 95% of the way up the y (cumulative frequency) axis, then along to the cumulative frequency curve, then down to the 95th percentile on the horizontal axis.
10,000 people were set to undertake an endurance run and the time taken is displayed below.. The 65th percentile is 8 hours.


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