4400 Higher June 2008 Paper 3 Q11

EdexcelHigherOld spec9 marksCumulative FrequencyGrouped Data

11 The table shows information about the pulse rates of 60 people, when they were resting.

Pulse rate
(\(p\) beats/min)
Frequency
\(50 \lt p \leqslant 60\)7
\(60 \lt p \leqslant 70\)21
\(70 \lt p \leqslant 80\)15
\(80 \lt p \leqslant 90\)14
\(90 \lt p \leqslant 100\)3
(a) Write down the modal class. (1)
(b) Work out an estimate for the mean pulse rate of the 60 people. (4)

The cumulative frequency graph gives information about the pulse rates of the same 60 people, after they have exercised for ten minutes.

Cumulative frequency graph, cumulative frequency 0 to 60 against pulse rate 90 to 140 beats per minute
(c) Use the graph to find an estimate for the median pulse rate of the 60 people. (2)
(d) Use the graph to find an estimate for the number of people with a pulse rate of more than 131 beats/min. (2)