AP Stats terms

Quantitative variable

represents numerical values that make sense to perform mathematical operations like addition or multiplication

“how many?” “how much”

ex: age, height, # of pets

Categorical variable

Values that represent groups, labels, or qualities. They sort data into distinct categories. It doesn’t make sense to perform numerical operations on these values.

ex: eye color, marital status (divorced, married), brand of a product (nike, adidas), fav movie genre (horror, comedy).

proportion

value that represents a fraction of a whole. its a way of summarizing data by showing the part of the group with the same characteristic.

ex: 100 students, 60 like comedy ; proportion of students who like comedy are 60/100 OR 0.60

Relative Frequency Distribution

shows the percentage/proportion of times each value or category appears.

ex: 50 people have brown hair, 30 blonde hair, 20 black hair.

• Brown hair: 50/100 =0.5 or 50%

• Blonde hair: 30/100=0.3 or 30%

• Black hair: 20/100=0.2 or 20%