- Mean: average Stem and leaf
- Mode: most repeated # - Sort data/find range
- Median: Middle #, n +1 / 2 - Select classes (5-15)
- Range: highest # - lowest #
- Find range
- Truncated: ALWAYS round down - Width = range/# of classes
- Nominal: No ranking - Midpoints = middle of
- Ordianal = ranking
- Interval = no def for 0, ex. Temperature “-2” -
- Ratio = 0 has a def
- Discrete= a limit
- Continuous = no limit
- The central tendency is the extent to which all the data values group around a typical or central
- The variation is the amount of dispersion or scattering of values
- The shape is the pattern of the distribution of values from the lowest value to the highest value.
n Standard Deviation
(X i X)
Where = arithmetic mean
n = sample size
th 1. Compute the difference between each value
X = i value of the variable X
i and the mean.
2. Square each difference.
3. Add the squared differences.
Coefficients of variation 4. Divide this total by n-1 to get the sample
CV S 100% 5. Take the square root of the sample variance
to get the sample standard deviation.