7th Grade · Statistics & Probability
Inference
7.SP.A.1
Definition
A conclusion about a population drawn from sample data. Valid inferences require a random, representative sample. The inference is an estimate subject to sampling variability.
Examples
- 50 students surveyed, 60% prefer math; estimate for all 500 students ≈ 300 prefer math.
- A non-random sample can produce a biased inference.
Key rule
The larger and more representative the sample, the more reliable the inference.
Memory hook
Use the sample to make a best guess about everyone.