- Descriptive stats/summary stats: quantities that capture important features of
- Most important are: location of frequency dist. And the spread.
- Most important is the proportion: fraction of observations in a given category
3.1 Arithmetic mean and standard deviation
- Mean is the most common metric to describe location of a freq. Dist.
- Standard deviation is most used to measure dist. Of spread.
- SAMPLE MEAN=average, line over Y ...ybar
- Standard deviation: measures how far from the mean the observations typically
are. ->calculated from the variance, square of the variance first take your value
and subtract the mean from it, then square it. Add all those numbers together
(sum of squares) then divide by one less than the total amount of observations,
then square root it
- Round to one decimal place bigger than your biggest decimal value in the
- Coefficient of variation (CV): calculates the standard deviation as a percentage of
the mean 1