Experiments: Calculations Flashcards
How do you work out mean?
Add all the raw scores and divide by how many data points there are
How do you work out mode?
Most common number appearing
How do you work out median?
Middle number, organise data in ascending order and find the middle number. If none, find the mean of the two middle numbers
How do you work out range?
Subtract the smallest number from the largest number. This gives a measure of dispersion
What is dispersion?
How far away each data point is from the mean
How do you work out variance?
- Find the mean
- Subtract the mean from each data point (number)
- Square the numbers you get
- Add all those new answers up
- Divide that number by the number of data points
How do you work out standard deviation?
Square root the variance
What is an advantage of using median?
Discounts outliers so not skewed
What is an advantage of using mode?
-Easy to calculate
-Always a whole value
-Can be done with qualitative data
What is an advantage of using range?
-Easy to calculate
-Shows the spread between the min and max values
What is an advantage of using variance?
-Takes into account all data variables in the set
-Less likely to be affected by outliers
What is an advantage of using standard deviation?
-Same units as original measure
-Easy to calculate if the variance is already done
What is an advantage of using mean?
Involves all the data
What is a disadvantage of using mean?
-Includes outliers which can skew result
-Can give decimal figures
What is a disadvantage of using median?
-Does not include all data collected
-May be a decimal figure
