Data Analysis

What is Data Analysis?

Data analysis is the information

• i.e. (facts and figures)

that have been collated in a way that allows them to be used to inform decision making.

What are Pie Charts?

A chart that is split into sectors to show:

• percentages/relative value of different categories of data.

How to calculate data as a proportion of 360° and amount of ________ sold?

Example

If the total sales of crisps in 2016 were 500,000 packets 40% of these were Cheese and Onion.

• 144/360 x 100 = 40%

• From there you can work out how many packets were sold for “Cheese and Onion”

• 500,000 x 0.40 = 200,000 packets sold were “Cheese and Onion”.

When to use a Pie Chart?

• For visual representation

• Great demonstration for market share

• Can compare sales of (e.g ice-cream/crisp flavours)

When NOT to use a Pie Chart?

• If needed to show increases/decreases of proportion overtime ——>(trends are not shown)

• Trying to identify relationship between 2 things

What is a Bar Chart?

• Data is usually grouped into categories using rectangular bars with the height of the bar representing the frequency for the category

• These bars can be presented vertically/horizontally

• One axis will show the categories being compared and the other axis will show the frequency.

When to use a Bar Chart?

• Data grouped into categories

• Summarise a large amount of date clearly

• Comparisons between different years

When NOT to use a Bar Chart?

• Needs to show qualitative data

• Oversimplifies data and further explanations may be needed

What is a Histogram?

• It’s the distribution of quantitative data by showing frequency of data points

• Represented through rectangles to show how frequently an outcomes occurs when data interval are successive

When to use a Histogram?

• Shape or distribution of large data set

• Displays chronological categories of numerical data

• If all data is numerical you can spot large differences in shape of the data

When NOT to use a Histogram ?

• Need to compare between different years

• Need to use exact values as the data is grouped into intervals

• Need to use large ranges

What is a Line Graph?

• Displays information using data points connected by line segments

• It shows trends and continuous changes over a continuous period

When to use a Line Graph?

• Need to compare 2 or more variables

• Need to present economic/financial data

• Need to show the business performance and analyse market trends

• Need to show changes overtime periods

When NOT to use a Line Graph?

• Need to use a large range of data then they become more difficult

• Start values of data are very different

• If you don’t have a lot of data otherwise line will imply you have more data than you collected

What is a Map?

• A map is only used to areas and geographical locations

• It uses clear shading ,clear keys and indicators

• Can be used to compare different regions

When to use a Map?

• If data is geographical

• Need to compare different countries/regions

• Need to present data in an attractive and effective way

When NOT to use a Map?

• If data does not relate to geographical areas

What are Index Numbers?

• Index numbers are used in order to make numerical data easier to understand

• They are a useful method of showing changes overtime in data

• E.g. price levels, consumer income levels or economic output.

• Using index numbers allows data to be standardised overtime so that the data is easily comparable.

How to work out questions using Index Numbers?

Worked Out Example: