Section 3 · Lecture 11 · Basics of Inference
The population mean μ is a fixed parameter. Every sample gives a different ȳ, and so a different confidence interval. Draw many samples and count how often the interval actually contains μ.
Confidence level, 1 − α
Sample size, n
How the interval is built
Take samples from the population N(μ = 50, σ = 10)
Where the sample means land
The confidence intervals
The most recent 50 intervals are shown, newest at the top. An arrow means the interval runs past the edge of the chart.
Intervals drawn
0
Intervals containing μ
—
Average interval width
—
Working it out: the latest interval
Examples from the lecture