Social Stats Unit 1 Week 3

x-axis

values of the variable

y-axis

frequency

bars do not touch

categorical data

bars touch

numerical data

normal distribution

symmetrical; one mode; mean, median, and mode are the same

bimodal distribution

not normal, has more than one peak

uniform distribution

no shape or pattern; looks like a block/box

skewed distribution

has tails (negative/left and positive/right)

Best central tendency for skewed distribution

median

Symmetrical distribution (normal curve)

mean and median are close

Assymmetrical distribution (skewed curve)

mean and median are further apart

Pearson’s median skewness

[(Mean-Median)*3)/SD]; know if distribution is skewed

If skewness calculation is greater than one (positive or negative)

skewed

if skewness calculation is less than one (positive or negative)

normal

Steam represents

tens

leaf represents

ones (have to be in perfect alignment)