๐งช What is Inferential Statistics?
Inferential statistics helps you make predictions or generalizations about a larger population based on a sample of data.
It answers the question:
"What can we infer about the population from this sample?"
๐ Key Concepts:
-
Population vs. Sample:
- Population = the whole group you're interested in.
- Sample = a smaller, manageable subset of the population.
-
Estimation:
- Using sample data to estimate population parameters (e.g. mean, proportion).
-
Hypothesis Testing:
- Testing assumptions (null vs. alternative hypothesis) to make conclusions.
-
Confidence Intervals:
- Range within which we believe the true population value lies, with a certain level of confidence (e.g., 95%).
-
P-value:
- Tells you the probability that the observed result is due to chance.
๐ง Real-World Examples:
- Politics: Predicting election results based on polls.
- Marketing: Testing if a new ad campaign performs better than the old one.
- Medicine: Determining if a new drug is more effective than the current treatment.
- Education: Using student samples to infer how all students are performing.
๐ Descriptive vs. Inferential:
Type | Purpose | Example |
---|---|---|
Descriptive Stats | Summarize data | "The average test score was 82." |
Inferential Stats | Make predictions or decisions | "We're 95% confident the average test score for all students is between 80 and 84." |
Would you like a simple example problem to see how inferential stats works in action?