Management Accounting · Summarising and analysing data

Presenting Data: Tables and Charts for ACCA Management Accounting

Updated 11 October 2026 · Fact-checked

Presenting data means summarising raw figures into a table or chart so patterns are easy to see. Group data into a frequency distribution, then choose the right display: bar chart for categories, pie chart for shares, histogram for grouped continuous data, ogive for cumulative totals. With unequal class widths, plot frequency density.

Understand Presenting Data: Tables and Charts

Raw data is a long list of numbers. It is hard to read. Presenting data means turning that list into something you can understand in seconds. You do this with tables and charts.

The starting point is a frequency distribution. You split the data into classes (for example 0 – under 10, 10 – under 20) and count how many items fall in each class. That count is the frequency. A cumulative frequency column adds the frequencies as you go down. A relative frequency is a frequency divided by the total.

Choose the chart to fit the data:

Bar chart: separate bars for categories or discrete values. Bars have gaps. Height shows the value. Width means nothing.
Pie chart: shows each category as a share of a total. Each angle = category ÷ total × 360°.
Histogram: for grouped continuous data. Bars touch. The area of each bar represents the frequency. With equal class widths, height can show frequency. With unequal widths you must plot frequency density.
Ogive (cumulative frequency curve): plot cumulative frequency against the upper class boundary. It is used to estimate the median and quartiles, and how many items fall below a value.

The key difference between a bar chart and a histogram: a bar chart compares separate categories, while a histogram shows the distribution of continuous data and uses area, not height, to show frequency.

Key formulas to remember

Class width: Class width = upper boundary − lower boundary; For 10 – under 20 the width is 10. Use boundaries, not stated limits, when classes have gaps.
Frequency density: Frequency density = frequency ÷ class width; Plot this on the vertical axis of a histogram when class widths are unequal.
Standard-width adjustment: Adjusted height = frequency ÷ (class width ÷ standard width); An alternative to frequency density. A class twice the standard width has its frequency halved.
Pie chart angle: Angle = (category value ÷ total) × 360°; Angles must add to 360°.
Cumulative frequency: Cumulative frequency = running total of frequencies; Plot against the upper class boundary for an ogive.
Relative frequency: Relative frequency = frequency ÷ total frequency; Can be shown as a fraction, decimal or percentage.
Median position on an ogive: Read the value at cumulative frequency = n ÷ 2; Quartiles are read at n ÷ 4 and 3n ÷ 4.

How to solve Presenting Data: Tables and Charts questions

Use this method for any question on tables and charts.

1Read the question. Is it asking you to build a table, pick a chart, calculate a value, or read a value from a chart?
2Identify the data type: categories, discrete numbers, or continuous grouped data.
3For grouped data, set out the classes, class widths and frequencies. Check the frequencies add to the total.
4Choose the chart: bar for categories, pie for shares of a whole, histogram for continuous classes, ogive for cumulative values.
5Do the calculation the chart needs: angles for a pie chart, frequency density for a histogram with unequal widths, cumulative frequency for an ogive.
6Check your work: angles total 360°, cumulative frequency ends at the total, and ogive points use upper boundaries.
7Match your result to the answer options. Check units, and whether the answer needs a number or a chart type.

Quickest way: Fast check for chart questions

When to use it: Use this in the computer-based test when you have about 1.2 minutes per two-mark question and need a safe shortcut.

Ask: are the classes of unequal width? If yes, the answer involves frequency density, not raw frequency.
For a histogram bar, compute frequency ÷ class width. Do not draw anything.
For a pie chart, divide 360° by the total first, then multiply by each value.
For an ogive, add the frequencies up to the class asked about and use the upper boundary.
Eliminate options that confuse chart types, such as a bar chart used for continuous grouped data.

Common mistakes in Presenting Data: Tables and Charts

Plotting raw frequency on a histogram with unequal class widths.
Students treat a histogram like a bar chart where height is frequency.
Fix: Remember area equals frequency. Divide each frequency by its class width and plot frequency density.
Plotting an ogive against the class midpoint or lower boundary.
Students copy the method used for other graphs.
Fix: Cumulative frequency is reached only at the end of a class, so plot it against the upper class boundary.
Drawing gaps between histogram bars, or no gaps between bar chart bars.
The two charts look alike, so the rules get mixed up.
Fix: Histogram bars touch because the data is continuous. Bar chart bars are separate because they show distinct categories.
Using the stated class limits to find width when there are gaps, such as 10 – 19 then 20 – 29.
Students subtract the stated limits and get 9 instead of 10.
Fix: Convert to boundaries first (9.5 – 19.5). The width is 10.
Pie chart angles that do not add to 360°.
Rounding errors or using the wrong total.
Fix: Use the grand total of all categories as the divisor, and check that angles sum to 360° before you answer.

Worked examples

Example 1

A histogram has these classes for delivery time in minutes: 0 – under 10 (frequency 20), 10 – under 20 (frequency 30), 20 – under 40 (frequency 40), 40 – under 80 (frequency 40). What is the frequency density of the 20 – under 40 class, and which class has the highest frequency density?

Show the solution

Class widths are 10, 10, 20 and 40.
Frequency densities: 20 ÷ 10 = 2; 30 ÷ 10 = 3; 40 ÷ 20 = 2; 40 ÷ 40 = 1.
The 20 – under 40 class has density 2.
The highest density is 3, in the 10 – under 20 class.

Answer: Frequency density of 20 – under 40 is 2. The 10 – under 20 class has the highest density (3), even though two classes have a higher frequency.

Example 2

A company has sales of $60,000 from Product A, $30,000 from Product B, $20,000 from Product C and $10,000 from Product D. It draws a pie chart of sales. What is the angle for Product C, and what is the cumulative share of sales from A and B together as a percentage?

Show the solution

Total sales = 60,000 + 30,000 + 20,000 + 10,000 = $120,000.
Angle for C = 20,000 ÷ 120,000 × 360° = 60°.
Share of A and B = (60,000 + 30,000) ÷ 120,000 = 90,000 ÷ 120,000 = 0.75.
Convert to a percentage: 75%.

Answer: Product C is 60° on the pie chart. Products A and B together make up 75% of sales.

Exam tips

In multiple-choice questions, watch for the trap of unequal class widths. If you see them, think frequency density straight away.
Know which chart suits which data. Many questions simply ask you to pick the best chart or state a difference between two charts.
For number entry questions, check the rounding instruction and whether the answer should be a percentage, an angle or a count.
When reading an ogive, always use cumulative frequency on the vertical axis and the upper boundary on the horizontal axis.
Use the on-screen calculator for angles and densities, and check totals before you confirm your answer.

Practice questions from Summarising and analysing data

Presenting Data: Tables and Charts in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

CMA FoundationTypes of Graphical Presentation: Charts, Graphs and Tables

Presenting Data: Tables and Charts: frequently asked questions

What is the difference between a bar chart and a histogram?

A bar chart compares separate categories or discrete values, with gaps between bars and height showing the value. A histogram shows grouped continuous data, with touching bars where area represents frequency. This is why unequal class widths need frequency density.

How do I draw a histogram with unequal class widths?

Work out each class width, then divide the frequency by the width to get frequency density. Plot frequency density on the vertical axis and the variable on the horizontal axis, with bars touching. The area of each bar then equals its frequency.

How do I build a frequency distribution table?

Choose non-overlapping classes that cover all the data, then count how many values fall in each class. Add a cumulative frequency column if needed. Check that the frequencies add up to the total number of observations.

What is an ogive used for?

An ogive is a cumulative frequency graph. You use it to estimate the median, quartiles and the number of items below or above a given value. Plot cumulative frequency against the upper class boundary and join the points.