Chalter 3+4 Flashcards
Central tendency
The most typical, central, or common score of a variable
3 measures of central tendency
Mean
Median
Mode
Mode
Most common score
Median
Score of the middle case
Mean
Average score
Dispersion
Variety, diversity, or amount of variation between scores
Measures of dispersion
Index of qualitative variation
Range, interquartile range
Variance, standard deviation
Mind the median
10,10,8,7,5,4,2
7
Find the range
10,10,8,7,5,4,2
10-2=8
x̄
Mean
Calculate x̄
10,20,30,40,50
150 ➗5= 30
What scores does the mean use
All scores
What is a skewed distribution
Pulling the mean
Positive skewed distribution
Pulls the mean to the right
Mean> median
Negative skewed distribution
Pulls the mean to the left
Mean< median
Unskewed distribution
In the middle
Mean= median
Doesn’t happen in fact