Edexcel GCSE Maths: Statistics

The table shows the times, in minutes, taken by $40$40 students to complete a puzzle.

Time, $t$t (minutes)	Frequency
$0 < t \leq 10$0<t≤10	$6$6
$10 < t \leq 20$10<t≤20	$11$11
$20 < t \leq 30$20<t≤30	$14$14
$30 < t \leq 40$30<t≤40	$9$9

(a) Work out an estimate for the mean time taken. (3 marks)

(b) Write down the modal class, and explain why your answer to (a) is only an estimate. (2 marks)

The cumulative frequency table shows the masses, in grams, of $80$80 apples.

Mass, $m$m (g)	Cumulative frequency
$m \leq 100$m≤100	$8$8
$m \leq 120$m≤120	$26$26
$m \leq 140$m≤140	$54$54
$m \leq 160$m≤160	$72$72
$m \leq 180$m≤180	$80$80

(a) Use the table to find an estimate for the median mass. (2 marks)

(b) Find an estimate for the interquartile range. (2 marks)

Here are seven numbers written in order:

$4, \quad 7, \quad 7, \quad 9, \quad 12, \quad x, \quad 20$4,7,7,9,12,x,20

The median of the seven numbers is $9$9 and the mean is $11$11.

(a) Work out the value of $x$x. (3 marks)

(b) Write down the mode of the seven numbers. (1 mark)

A farmer has $1500$1500 sheep. She wants to take a stratified sample of $60$60 sheep across three fields. The numbers of sheep in the fields are:

Field	A	B	C
Number of sheep	$450$450	$600$600	$450$450

Work out how many sheep should be sampled from each field. (3 marks)

The table shows how $36$36 people travelled to work. This information is to be shown in a pie chart.

Method	Car	Bus	Walk	Cycle
Frequency	$15$15	$9$9	$8$8	$4$4

Work out the angle of the sector that represents Car. (2 marks)

Here are six numbers:

$3, \quad 8, \quad 8, \quad 10, \quad 15, \quad 20$3,8,8,10,15,20

Write down the range of these numbers. (1 mark)