15.1 - Statistics & Diagrams
The role of statistics in business
Businesses generate a wide range of numerical information, such as figures on sales volumes, operating costs, income from revenue, overall profit levels, and results from market research. These statistics are vital for assessing how well a business is performing and for predicting future trends or outcomes. Presenting this data in clear, visual formats helps make the information easier to understand and apply in decision-making processes.
Methods of presenting data using charts and graphs
Various types of charts and graphs can be used to display business data effectively. Each method has specific features that make it suitable for different kinds of information, allowing businesses to communicate figures in a visually appealing and accessible way.
Pie charts
Pie charts display proportions of a whole, such as the breakdown of market share among competitors. The full circle represents 100%, with each segment showing a percentage of the total.
To calculate the angle for each segment:
Where:
- Percentage = Share of the total (%)
- 3.6 = Degrees per 1% (360° ÷ 100)
Pie charts are straightforward to create, often using spreadsheet software, and provide a quick visual summary that is easy to interpret.
Bar charts
Bar charts compare different values for a single category, such as sales figures across various products. They consist of rectangular bars where the length or height represents the value, making them simple to build and read. Their strong visual appeal helps highlight differences clearly.
Histograms
Histograms resemble bar charts but are designed for data with continuous ranges, such as frequency distributions over intervals.
Key differences from bar charts:
- The area of each bar (not just height) corresponds to the value.
- Bars touch without gaps to show continuity.
- Bar widths can vary to reflect different interval sizes.
This makes histograms ideal for analysing data with wide variations, like customer age groups in market research.
Pictograms
Pictograms enhance bar charts or histograms by replacing plain bars with images or symbols related to the data, such as company logos. For example, a sports equipment firm might use icons of footballs to represent sales units. These are commonly featured in promotional materials to make data more engaging.
Line graphs
Line graphs illustrate the relationship between two variables over time, such as monthly revenue trends. Points are plotted and connected by lines, allowing multiple datasets to be compared on the same graph using distinct colours for clarity. This format is effective for showing patterns like growth or decline.
Worked example - Calculating angles for a pie chart
A business has a total market of 100%, divided as follows: Company A with 30%, Company B with 35%, Company C with 20%, and Company D with 15%. Calculate the angle in degrees for Company A's segment.
Step 1: Identify the values
- Percentage for Company A = 30%
- Degrees per 1% = 3.6
Step 2: Apply the formula
Step 3: Perform the calculation
Ways in which diagrams can mislead
Diagrams can sometimes distort data, leading to incorrect interpretations. For instance, starting a graph's scale at a number other than zero can exaggerate changes, making small increases appear much larger. Businesses must ensure scales are appropriate to avoid giving false impressions.
Skills for analysing business data
Simply viewing charts is not enough; effective analysis involves examining data to uncover meaningful insights. This includes spotting key patterns, such as steady increases in quarterly online orders, and exploring their causes and implications. For example, a drop in gym membership sign-ups could stem from a rival launching a competing service, prompting the business to respond with targeted promotions.