Statistics Unit 1 Quiz Review

Variable

A raw characteristic that can take on different values and describe a situation

Data

The raw material collected by observing, measuring, counting, or asking questions

Population

The entire group being studied

Sample

A smaller group selected from the population

Descriptive statistics

Collecting, organizing, summarizing, and presenting data

Inferential statistics

Using a sample to generalize or predict about a larger population

Random sampling

Selecting subjects using chance methods so everyone has an equal shot

Systematic sampling

Selecting every kth subject from a numbered list

Observational study

Watching whats happening without interference

Experimental study

Manipulating a variable to see how it affects another variable

Qualitative

Data sorted into categories or labels - not numbers you’d do math on

Quantitative

Data thats numerical - can be ordered, ranked, or measured

Discrete

Values you can count - whole numbers, no in-between

Continuous

Values obtained by measuring - any value between two points

Nominal

Categories only. Just labels

EX: eye color, political party

Ordinal

Categories that can be ranked

EX: class rank, letter grades

Interval

Ranked with equal gaps between values

EX: Temperature (F), IQ score

Ratio

Everything an interval has, plus a true zero

EX: weight, height, age

Confounding variables

an outside variable that affects the outcome but wasnt separated from the independent variable

EX: subjects on an exercise program also happen to eat better without telling the researcher