unit 1 Lesson 2

Descriptive statistics

Organizing and summarizing data with and graphs

Frequency distribution

Lists each category of data and the number of occurrences for each category

Relative frequency

Proportion (orpercent) of observations within u category. Lists each category of data together with the relative frequency

Classes

Group of Dutch values

Lower class limit

Lower valve withincless

Upper class limit

Largest value within class

Class width

Difference between consecutive lower class limits

Histogram

Drawing rectangles for each class. Height can be frequency or relative frequency. Width is same and they touch

Uniform distribution

Frequency of values is spread evenly across variable

Symmetric distribution

Highest frequency occurs in middle, frequencies tail Off on right and left

Skewed right

Tail to the right of the peak is longer than tail to the left of the peck

Skewed left

Tail to the left of the peak is longer than the tail to the right of the peak