# Lesson Worksheet: Percentiles and Quartiles Mathematics

In this worksheet, we will practice computing percentiles and quartiles from a given data set.

Q1:

A ski jump event tracked the distance jumped by skiers in the grouped frequency table shown.

 Time Taken (Minutes) Frequency 160≤𝑚<180 180≤𝑚<200 200≤𝑚<220 220≤𝑚<240 240≤𝑚<260 2 23 45 16 1

Estimate the value of the 55th percentile of the distance jumped by skiers in the event. Give your answer to one decimal place.

A claim is made that at least of the skiers jumped less than 231 m. By estimating a suitable percentile, is this claim valid?

• ANo, we can estimate that the 90th percentile is 232 m to one decimal place, and this would imply that too many skiers jumped further than 231 m.
• BYes, we can estimate that the 90th percentile is 230.6 m to one decimal place, so of the data will lie below this value.
• CNo, we can estimate that the 89th percentile is 231.1 m to one decimal place, so of the data will lie below this value. Therefore, the claim is incorrect.
• DYes, we can estimate that the 90th percentile is 230.4 m to one decimal place, so of the data will lie below this value.

This lesson includes 9 additional question variations for subscribers.