Measures of Location and Spread Flashcards
What are the measures of location?
- Mean
- Median
- Mode
- upper quartile
- lower quartile
What is the mode?
the number that appears the most.
When is using the mode not useful?
when not number appears more than once.
What is the median?
the middle number.
When is using the median useful?
when you have extreme values
What is the mean?
When is using the mean not useful?
when you have extreme values.
Why does the mean give a true measure of the data?
it takes into account all the data.
How do you calculate the mean?
How do you calculate the mean in a cumulative frequency table?
How do you calculate the mean in a grouped frequency table?
How do you find the upper and lower quartiles of discrete data?
- To find the lower quartile you divide n by 4.
- To find the upper quartile you find 3/4 of n.
- If the number you get is whole then the lower or upper quartile will be the midpoint between that number and the next number. If it is not whole then round up and pick that number.
How do you find the upper and lower quartiles of continuous data?
interpolation
What are the measures of spread?
- Range
- Interquartile range.
- Variance
- Spread
How do you measure the variance?
How do you measure standard deviation?
What is coding?
Turning the values you have into different values that are easier to deal with.
What are the rules for coding regarding the mean?
you can multiply and add.
What are the rules for coding regarding the standard deviation?
you can only multiply and divide
