Section+7

Center

Spread- the range of the data from end to end

Variability- the amount that the data changes/ is different

Shape- 3rd important feature of a distribution. Sometimes shapes arise that often have to have their own names. The shape may be skewed or symmetric.

Symmetric- the one side is a rough mirror image of the other side. Example: Y_O_I_H mirrors H_I_O_Y

Skewed-Off balanced...tail extends toward smaller values or larger

Outliers- Unusual features in distribution...Or values that disagree with established patterns of most data.

Histogram-A graphical analysis of tabulated frequencies, shown as bars. It shows what proportion of cases fall into each of several categories. The categories are usually specified as non-overlapping intervals of some variable. The word proportion is not correct. Check the definition for frequency.

__Bins__- Subintervals in a histogram.

Frequency- the number of times an observational unit occurs in a bin of a histogram

Relative Frequency- term for proportion; it is the value calculated by dividing the number of times an event occurs by the total number of times an experiment is carried out. The probability of an event can be thought of as its long-run relative frequency when the experiment is carried out many times. Is relative frequency only for experiments? back