Question 6 - A-Level Maths

Exam Board	CAIE
Module	S1 (Statistics 1)
Year	2014
Session	June
Topic	Data representation
Type	Complete frequency table and histogram together

6 The times taken by 57 athletes to run 100 metres are summarised in the following cumulative frequency table.

Time (seconds)	\(< 10.0\)	\(< 10.5\)	\(< 11.0\)	\(< 12.0\)	\(< 12.5\)	\(< 13.5\)
Cumulative frequency	0	4	10	40	49	57

State how many athletes ran 100 metres in a time between 10.5 and 11.0 seconds.
Draw a histogram on graph paper to represent the times taken by these athletes to run 100 metres.
Calculate estimates of the mean and variance of the times taken by these athletes.