Statistics

Statistics

1. Numerical Data

   • Discrete
     • Always takes a certain value
       • Number of goals scored in a match
   • Continuous
     • It can never be measured exactly. Only within a certain range
       • Top speed of a car
   • Numerical Data must be measured or counted

2. Categorical Data

   • Nominal
     • Cannot be organised into an ordered list
       • Locations from around the world
   • Ordinal
     • Can be organised into a list
       • Release dates of movies
   • Categorical Data can only be described
     • By: Michéal O'Dwyer

3. Statistical Investigation

   • Pose a Question
     • Collect Data
       • Present Data
         • Interpret Resuts
           • Repeat

4. Planning a Survey

   • Decide
     • What you want to find out
     • What data you want to collect
     • How much of this data you want to collect

5. Types of Surveys

   • Face to Face
   • Postal
   • Online
   • Telephone

6. Questionnaire Guidelines

   • Be clear on what you want to find out
   • Ask short simple questions that are easy to understand
   • Avoid embarrasing and leading questions

7. Averages

   • Mean
     • Add up the numbers and divide by the amount of numbers
   • Mode
     • The most frequent answer collected
   • Median
     • Put data in order and find the answer given in the middle
   • The range is the difference between the highest and lowest value

8. Presenting Data

   • Tally
   • Bar Chart
   • Stem and Leaf Diagram

9. Primary Data

10. Secondary Data