What is what does p with a line over it mean?

$\bar{p}$ generally represents the sample proportion in statistics. It's a point estimate for the population proportion which is often denoted as p.

Here's a breakdown:

• Definition: $\bar{p}$ is calculated as the number of successes in a sample (often denoted as x) divided by the sample size (often denoted as n): $\bar{p} = \frac{x}{n}$.

• Purpose: It's used to estimate the true proportion p of a characteristic within a larger population based on the observed proportion in a smaller, representative sample.

• Usage: $\bar{p}$ is frequently used in:

  • Hypothesis Testing involving proportions.
  • Constructing Confidence Intervals for population proportions.

• Relationship to Population Proportion (p): $\bar{p}$ is an estimator of p. Ideally, $\bar{p}$ should be close to p if the sample is truly representative of the population. The Law of Large Numbers suggests that as the sample size (n) increases, $\bar{p}$ gets closer to p.