Notes

Outline

Standard deviation: ungrouped data

Standard deviation: grouped data

Standard deviation example: scores on a midterm

Standard deviation:  calculating formula

Standard deviations: calculating formula

Standard deviation: calculating formula

Standard deviation If the population is normally distributed, you can estimate the percentage of the population within 1, 2, and 3 standard deviations of the mean: 68% of cases lie +/- 1 s.d. of mean 95% of cases lie +/- 2 s.d.’s of mean 99.9% of cases lie +/- 3 s.d.’s of mean

Standard deviation