Final answer:
In the confidence interval formula, 'p' is the sample proportion, 'z' is the z-value for the confidence level, 'n' is the sample size, and 'Pie' (implied as 'p' in the actual formula) represents the population proportion being estimated.
Step-by-step explanation:
The formula p ± z \sqrt{p(1-p)/n} is used to calculate a confidence interval for the population proportion. Here, each variable has a specific meaning:
- p represents the sample proportion, which is the proportion of successes in our sample.
- z corresponds to the z-value associated with the confidence level; this value is found from the standard normal distribution.
- n indicates the sample size, which is the total number of observations in our sample.
- Pie (π) is the population proportion that we are trying to estimate.
In conclusion, a matches with 'the sample proportion', b with 'the value associated with the confidence level', c with 'the sample size', and d (although represented as Pie in the question) with 'the population proportion that is being estimated'.