Stats quiz (summarizing, descriptive stats)

Frequency distribution table

• Total frequency is equal to number of elements

• Frequencies are how much of each selection for a variable which are called classes

Relative Frequency (RF)

• fraction of items that belongs to each class

• RF = F/T

• Total RF equals 1

Percent Frequency (PF)

• Percentage of items that belong to each class

• PF = RF x 100%

• Total PF equals 100%

Cross tabulation

• table summarizing 2 or more variables at a time

Joint value

• Value that describes 2 variables

Marginal value

Describes total for only one variable

2 types of graphs

a) Bar chart

b) Pie chart

computing quantitative frequency

4 steps:

• Rank data from least to greatest

• Identify max and min

• choose number of classes (K)

• compute class width (Cw)

Equation: Cw = max-min/K