Measures of central tendency Flashcards
How do you work out the mean?
- Add up all values in the data set
- Divide by the number of values in the data set
What is the strength of using the mean?
It is representative of the whole data
What is the limitation of using the mean?
Any extreme score will distort the data
How do you work out the mode?
- Find the most frequently occurring value
What is the strength of using the mode?
It isn’t affected by extreme values
What is the limitation of using the mode?
It doesn’t represent the whole data set
How do you work out the median?
- It is the middle value when they are placed in order
What is the strength of using the median?
It isn’t influenced by extreme values
What is the limitation of using the median?
It can be distorted by small samples
What are the two ways we can measure dispersion?
- Range
- Standard deviation
How do you work out the range?
Highest value - lowest value + 1
What are the strengths of using the range?
- Easy to work out
- Takes into account extremes of data
What are the limitations of using the range?
- Can be influenced by one score
- Doesn’t measure general spread of data
What are the strengths of using the standard deviation?
- Takes into account all scores
- Provides a sensitive measure of dispersion
What is the limitation of using the standard deviation?
As it takes into account of all scores it can be distorted by extreme values
