Descriptive stats: location Flashcards
What are descriptive stats?
Quantities that capture important features of a frequency distribution
What are the 3 descriptive stats for location?
Mean, median, mode
What is the most common metric to measure the location of a frequency distribution?
Mean
What is the mean?
Average of a set of measurements
What is sample mean?
Average of all measurements in a sample
What is the mode?
The most frequent measurement/highest peak in the frequency distribution
Do data sets often have a mode?
No, but will often have a peak
Is the mode very useful?
No
What is the median?
The middle measurement in a set of ordered data
How is the median related to percentiles?
Is the 50% percentile
Why is the median second only to the mean in terms of importance?
Usually mean is a pretty good representative of the centrepoint of the data, but with skewed data the median is better
How do you calculate the median with an even number of measurements?
Can either report both middle values or use the average of the two
Is it good when the mean is close to the median?
Very good
Why is the median a better representative of the midpoint of the data when the data is skewed?
Mean is very sensitive to outliers and extreme values
