Statistical Inference & Prediction
📋 What it is
Inference uses a sample to make a reasonable prediction about a whole population.
🗣️ Coach says
You can't survey everyone, so you survey a sample and infer the rest. If 60% of a fair sample likes pizza, you predict about 60% of everyone does. Good inference needs a fair, big-enough sample.
🧠 Memory hook
Sample → infer the whole. The bigger and fairer the sample, the safer the prediction.
😂 Giggle
Why did the probability student bring an umbrella to school on a sunny day?
Because there was a non-zero chance of rain!
😲 Whoa!
Election forecasts poll only a few thousand people to predict millions of votes — inference done well.
✅ Quick check: In a fair sample, 60% prefer apples. What can you reasonably predict about the whole group?
Say your answer out loud first — then reveal.
About 60% of the whole group likely prefer apples too.
A representative sample lets you infer the population's proportion.
🧪 Try it! (2 minutes)
Ask 10 classmates a yes/no question and predict how the whole class would answer.