All Flashcards
Explain the concept of the Random Sample condition.
Reduces bias and allows results to be generalized to the larger population.
Explain the concept of the Independence condition.
Ensures that one subject's data doesn't influence another's, often checked using the 10% rule.
Explain the concept of the Normal condition.
Allows us to use the normal distribution (z-scores) for calculations; checked using the Large Counts condition.
Explain the impact of sample size on the margin of error.
Larger sample sizes lead to smaller standard errors, resulting in smaller margins of error and more precise estimates.
Explain the meaning of the confidence level.
The success rate of the method, not the probability of the interval containing the true parameter.
What are the differences between point estimate and margin of error?
Point Estimate: Best single guess for population proportion, center of the interval | Margin of Error: Buffer zone for uncertainty, based on critical value and standard error.
What are the differences between confidence level and confidence interval?
Confidence Level: Success rate of the method | Confidence Interval: Range of values estimating the population parameter.
What are the differences between random sampling and non-random sampling?
Random Sampling: Reduces bias, allows generalization to the population | Non-Random Sampling: Introduces bias, limits scope of inference.
What are the differences between a large and small margin of error?
Large Margin of Error: Less precise estimate, wider interval | Small Margin of Error: More precise estimate, narrower interval.
What are the differences between using p=0.5 and an estimated p when calculating sample size?
Using p=0.5: Finds the maximum sample size needed, conservative approach | Using Estimated p: Can result in a smaller sample size if the estimate is accurate.
What is the definition of confidence interval?
A range of values, calculated from sample data, used to estimate a population parameter.
What is the definition of sample proportion?
Our best single guess for the population proportion, denoted as p̂.
What is the definition of margin of error?
A buffer zone to account for uncertainty, added and subtracted from the point estimate.
What is the definition of critical value?
The z-score determined by the confidence level (e.g., 1.96 for 95%).
What is the definition of standard error of the proportion?
Variability of the sample proportion.