Practice question · Multiple choice
A 95% confidence interval for a mean is often confused with a range containing 95% of the data. What is the difference?
Hints
- Ask what happens to each as goes to a million.
- One is about a parameter; the other about the next observation.
Show the answer
B. The interval estimates where the MEAN lies, and shrinks as n grows
Why
Averaging pins down a mean and does nothing to reduce individual spread. A confidence interval can be a millimetre wide while individual heights still vary by 30 cm.
Practise Confidence Intervals and Estimation
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