Why use Statistics? Discuss.

Statistics Wednesday, April 19, 2023

Statistics Wednesday, April 19, 2023

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.

For example:

• “Four in ten criminal offenders in the USA report alcohol as a factor in violence.”

Statistics Wednesday, April 19, 2023

• “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.

Statistics Wednesday, April 19, 2023

Types of Data:

We need to observe or measure things to get data. This observation is called a variable.

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

Statistics Wednesday, April 19, 2023

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

MEASURABLE

The units of measurement (eg. CDs) cannot be split up; there is nothing between 1 CD and 2 CDs.

COUNTABLE

Statistics Wednesday 19 April 2023

Decide whether or not the following are continuous or discrete:

a) Shoe size:

b) Gender:

c) The numbers of chocolates in a box:

d) Times taken for athletes to run 100m:

Discrete because can only take specific values, eg, 7, 8, 8.5. Cannot get a size 8.35

Discrete because can only be male or female.

Discrete.

Time is continuous

Discrete and continuous data

Which data is discrete and which is continuous?

1. the number of pages in a book

2. the amount of money in a piggy bank

3. the men's 100m sprint record time

4. the number of Smarties in a tube

5. the capacity of a car's petrol tank

6. the length of your shoe

7. the number of hairs on your head

8. your age

9. the temperature in Bulwell

10. your shoe size

Answers

1. discrete

2. discrete

3. continuous

4. discrete

5. continuous

6. continuous

7. discrete

8. continuous

9. continuous

10. discrete