Descriptive stats 2

Question 1

what are the 4 measures of variability?

Answer 1

range
inter-quartile range
variance
standard deviation

Question 2

what is the range?

Answer 2

simplest measure of variation
calculated min - max
- can be skewed by extreme scores/ outliers so may not provide an accurate representation of variability

Question 3

what’s the interquartile range

Answer 3

calculated: 25th percentile - 75th percentile
+ focuses on the middle of the data and so is less affected by outliers

Question 4

what’s standard deviation

Answer 4

calculated by the square root of the variance

Question 5

what’s variance

Answer 5

measure of how spread out the values in the dataset are
calculated by taking the average of the squared differences between each value and the mean

Question 6

what’s a coefficient of variation

Answer 6

useful when comparing datasets with different units/ scales
calculated by dividing the standard deviation by the mean and multiplying by 100

Question 7

what’s trimming?

Answer 7

removing a certain percentage of extreme scores from the data before recording them