Representation and summary of data - Chapter two

Representation and summary of data - Chapter two

1. Quantitative variables - variables associated with numerical observations.

2. Qualitative variables - variables associated with non-numerical observations.

3. Continuous variable - a variable that can take any value in a given range

4. Discrete variable - a variable that can take only specific values in given range

5. The mode - the value that occurs the most often

6. The median - the middle value when the data is put in order

   • When n/2 is a whole number find that number and then number after (above it) for example if n was 10 then you find the 5th and 6th integers and do the midpoint of them.
   • When n/2 is not a whole number round the number up and use that term, for example if n was 11 when you divide it by two you get 5.5 so use the 6th term.

7. The mean - the sum of all the observation divided by the total number of observations

8. Coding - makes large numbers easier to work with

   • When converting a coded mean to the original mean, both subtracting/adding and multiplying/dividing make an impact so you need to do the opposite of both.

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