Section 2 · Lecture 09 · Sampling Distribution
In the population, the proportion of people with blood type A is a fixed number, the parameter p. Each random sample gives a sample proportion p̂, a statistic that changes from sample to sample. Collect many samples to build the sampling distribution of p̂.
Population proportion, p (fixed)
Sample size, n
Take samples
The population
Parameter: p =
Each dot stands for 1% of a large population. This never changes.
The latest sample
The sampling distribution of p̂
Samples drawn
0
Average of all the p̂ values
—
Samples with p̂ within ±0.10 of p
—
Working it out
Where the distribution is centred
The distribution of p̂ in a table