1. Why use Statistics? Discuss.
22nd February 2005
Why use Statistics? Discuss.

2. Statistics 22nd February 2005
Objective: To understand the use and application of statistics and identify different types of data.
Statistics is used when you want to make sense of large amounts of data or information.
However, when collecting and interpreting data, it is important to understand how reliable the data is.

3. Statistics 22nd February 2005 For example:
“Four in ten criminal offenders in the USA report alcohol as a factor in violence.”
“47% of people in Great Britain supported the ban on fox hunting with dogs” (2, 234 people interviewed, Mori Survey)
Question: What are the possible problems with such statements? Do the facts represents the view of all people? Discuss.

4. Statistics Types of Data: 22nd February 2005
We need to observe or measure things to get data. This observation is called a variable.
Types of Data:
Quantitative variables:
Qualitative variables:
These have numerical observations, such as
shoe size (7, 8, 9, 7.5, 8.5)
Height (178cm, 1.9m) and weight.
Variables that have non-numerical observations, eg. Eye colour,
Favourite food

5. Statistics 22nd February 2005
Quantitative variables can be broken down further.
Quantitative variables:
Continuous data
Discrete data
…Are measured on a scale and can take any value eg. height
The units of measurement (eg. CDs) cannot be split up; there is nothing between 1 CD and 2 CDs.

6. Statistics 22nd February 2005
Decide whether or not the following are continuous or discrete:
Discrete because can only take specific values, eg, 7, 8, 8.5. Cannot get a size 8.35
a) Shoe size:
b) Gender:
Discrete because can only be male or female.
c) The numbers of chocolates in a box:
Discrete.
d) Times taken for athletes to run 100m:
Time is continuous

7. Discrete and continuous data
Which data is discrete and which is continuous?
the number of pages in a book
the amount of money in a piggy bank
the men's 100m sprint record time
the number of Smarties in a tube
the capacity of a car's petrol tank
the length of your shoe
the number of hairs on your head
your age
the temperature in Bulwell
your shoe size
Answers
discrete
continuous