14. The main measures of central tendency: mean, median and mode

15. Mean, median and mode.

16. Measuring skewness

Quiz 8: Skewness

17. Skewness. Exercise

18. Measuring how data is spread out: calculating variance

19. Variance. Exercise

20. Standard deviation and coefficient of variation

Quiz 9: Standard deviation

21. Standard deviation and coefficient of variation. Exercise

22. Calculating and understanding covariance

23. Covariance. Exercise

24. The correlation coefficient

Quiz 10: Correlation

25. Correlation coefficient. Exercise