USAT Statistics MCQs

Parameters describe populations, such as a population mean or proportion.
They are often unknown and estimated using sample statistics.

A statistic summarizes observed sample data.
It may be used to estimate a corresponding population parameter.

Qualitative variables describe categories rather than numerical amounts.
Blood groups such as A, B, AB, and O are categories.

A discrete variable takes countable values, usually integers.
The number of students cannot meaningfully take fractional values.

Continuous variables can take any value within an interval.
Weight can be measured to increasingly fine precision.

Nominal data classify observations without ranking them.
Examples include blood group and marital status.

Ordinal data preserve order among categories.
The gaps between successive categories need not be equal.

Interval scales support meaningful differences between values.
Temperature in degrees Celsius has no true absence point.

A population contains every unit about which conclusions are desired.
A sample is selected from the population for practical study.

A sample provides information about a larger population.
Good sampling methods aim to make it representative.