GCSE · Data representation

Frequency polygonsExam-style questions

Turn a grouped frequency table into a frequency polygon (each frequency plotted at the midpoint of its class, the points joined with straight lines) and read one back into a table. Find the modal class, the class containing the median and an estimate of the mean from a polygon, compare two polygons on one grid in context, and spot the mistakes that cost marks.

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15 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAll Level 2 Level 3 Level 4

The table shows information about the masses of

50

tomatoes.

Mass ( $m$ grams)	Frequency
$40 < m \le 50$	$6$
$50 < m \le 60$	$11$
$60 < m \le 70$	$17$
$70 < m \le 80$	$10$
$80 < m \le 90$	$6$

Draw a frequency polygon for this information.(2 marks)

Level 2 · 2 marksTry it

2
The table shows information about the times, $t$ minutes, that $30$ people took to complete an online survey.
Time ( $t$ minutes) Frequency
$0 < t \le 10$ $2$
$10 < t \le 20$ $9$
$20 < t \le 30$ $13$
$30 < t \le 40$ $6$
Kyle is going to draw a frequency polygon for this information.

Write down the coordinates of the four points he should plot.

(2 marks)
Level 2 · 2 marksTry it
3
The table shows information about the times, $t$ minutes, that $30$ students spent reading on Sunday.
Time ( $t$ minutes) Frequency
$0 < t \le 10$ $6$
$10 < t \le 20$ $11$
$20 < t \le 30$ $9$
$30 < t \le 40$ $4$
Four students each drew a diagram for this information.

Diagram 1Diagram 2Diagram 3Diagram 4(a) Which diagram is a correct frequency polygon for the information in the table? Write down its number.

(1 mark)
(b) Explain what is wrong with Diagram 4.

(1 mark)
Level 2 · 2 marksTry it

Time ( $t$ minutes)	Frequency
$0 < t \le 10$	$2$
$10 < t \le 20$	$9$
$20 < t \le 30$	$13$
$30 < t \le 40$	$6$