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O-Level E-Math · 2021 · P1 Q13 Statistical diagrams · Reading a comparative bar chart 4 marks: 1 + 1 + 2 · statistics (comparing distributions) difficulty 3 of 5

O-Level E-Math 2021 Paper 1, Question 13: Reading a comparative bar chart

The answer

(a) \(\approx 465\,000\)
(b) the 0 to 9 bar is shorter in 2017
(c) mean age has increased

O-Level E-Math 2021 Paper 1 Question 13 · Verified worked solution by the Genius Plus Academy teaching team

What this question tests

This is Question 13 of the O-Level E-Math 2021 Paper 1. It tests reading a comparative bar chart, in the Statistical diagrams area. It is worth 4 marks: 1 + 1 + 2. It is a worded / diagram-based question, so open your Ten-Year Series (TYS) or the official paper at this question, then follow our full worked solution below.

Step-by-step solution

(a) Reading the 2017 bar for the 60 to 69 group (\(\approx 4.65\) in units of 100 000) gives about \(465\,000\) people.

(b) The 0 to 9 age group (the most recent births) has a smaller bar in 2017 (\(\approx 385\,000\)) than in 2007 (\(\approx 420\,000\)), so fewer young children, evidence of a falling birth rate.

(c) The mean age has increased between 2007 and 2017: the younger groups (0 to 19) are smaller in 2017 while the older groups (60 to 89) are larger, so the distribution has shifted towards older ages.

Answer: (a) \(\approx 465\,000\)
(b) the 0 to 9 bar is shorter in 2017
(c) mean age has increased

Same structure, different numbers

A question is hard because of its structure, not its surface.

Swap the constants, dress a quadratic as a length, hide a derivative inside an integral, and a student sees a brand new problem. The structure underneath is the same, and so is the method. Once a student can name the structure, a whole row of questions that look different start to open the same way.

That is where marks really leak: in choosing the method, not in the algebra that follows. We call it Lock and Key, name the lock, then the key follows.

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What does O-Level E-Math 2021 Paper 1 Question 13 test?

It is a reading a comparative bar chart question from Statistical diagrams, worth 4 marks: 1 + 1 + 2.

Is this the same as IP Math?

Yes. IP (Integrated Programme) schools teach the same O-Level Mathematics content; they just sequence it differently and set their own internal exams, so these worked solutions apply to IP students too.

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