CIE iGCSE Maths C9.4 Statistical charts and diagrams Exam Style Practice Questions- Paper 1
▶️ Answer/Explanation
(a)
Draw a bar for August at a height of \(4\) on the vertical axis, the same width as the other bars.
✅ Answer: Bar for August drawn at height 4.
(b)
Add all six values: \(3 + 9 + 7 + 11 + 8 + 4 = 42\).
Divide by the number of months: \(\text{Mean} = \dfrac{42}{6} = 7\).
✅ Answer: \(7\)
▶️ Answer/Explanation
(a)
First, sort the given data in ascending order: \(4, 4, 8, 10, 13, 14, 16, 17, 19, 23, 27\).
Group the numbers by their tens digits (the stems).
Stem \(0\): \(4, 4, 8\)
Stem \(1\): \(0, 3, 4, 6, 7, 9\)
Stem \(2\): \(3, 7\)
✅ Answer:
(b)
The median is the middle value of the sorted data set.
Since there are \(11\) values, the median is the \(6^{\text{th}}\) value.
Looking at our ordered list, the \(6^{\text{th}}\) value is \(14\).
✅ Answer: \(14\)
▶️ Answer/Explanation
(a) The total circle corresponds to 90 people and has $360^{\circ}$. Pop occupies a sector angle of $120^{\circ}$. To find the number of people, we multiply the fraction by the total population: $$\text{Pop people} = \frac{120^{\circ}}{360^{\circ}} \times 90 = \frac{1}{3} \times 90 = 30$$
(b) Use a protractor to measure an angle of $80^{\circ}$ adjacent to one of the existing sector boundaries and draw a straight line to form the Classical sector.
(c) (i) To convert the 9 jazz lovers into a degree measure on our pie chart, we find their proportional share of $360^{\circ}$: $$\text{Jazz angle} = \frac{9}{90} \times 360^{\circ} = \frac{1}{10} \times 360^{\circ} = 36^{\circ}$$ (ii) Use your protractor to construct a $36^{\circ}$ sector for Jazz. The remaining unlabelled sector left over will automatically be Folk.
Answers:
(a) 30
(b) [Draw $80^{\circ}$ angle sector]
(c) (i) 36
(ii) [Construct $36^{\circ}$ sector and label remaining as Folk]