Transcript Statistics
Statistics Saturday, 09 April 2016 Why use Statistics? Discuss. Statistics Saturday, 09 April 2016 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. Statistics Saturday, 09 April 2016 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. Statistics Saturday, 09 April 2016 We need to observe or measure things to get data. This observation is called a variable. Types of Data: Quantitative variables: These have numerical observations, such as shoe size (7, 8, 9, 7.5, 8.5) Height (178cm, 1.9m) and weight. Qualitative variables: Variables that have nonnumerical observations, eg. Eye colour, Favourite food Statistics Saturday, 09 April 2016 Quantitative variables can be broken down further. Quantitative variables: Continuous data …Are measured on a scale and can take any value eg. Height MEASURABLE Discrete data The units of measurement (eg. CDs) cannot be split up; there is nothing between 1 CD and 2 CDs. COUNTABLE Statistics Saturday, 09 April 2016 Decide whether or not the following are continuous or discrete: a) Shoe size: Discrete because can only take specific values, eg, 7, 8, 8.5. Cannot get a size 8.35 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 Discrete and continuous data Which data is discrete and which is continuous? Answers 1. the number of pages in a book 1. discrete 2. the amount of money in a piggy bank 2. discrete 3. the men's 100m sprint record time 3. continuous 4. the number of Smarties in a tube 4. discrete 5. the capacity of a car's petrol tank 5. continuous 6. the length of your shoe 6. continuous 7. the number of hairs on your head 7. discrete 8. your age 8. continuous 9. the temperature in Bulwell 9. continuous 10. your shoe size 10. discrete