Key Concepts
- Confidence Intervals: The plausible range around an estimated statistic, derived from the margin of error.
- Using Sample Data for Decision Making: Sample statistics help predict outcomes but always include uncertainty.
- Limitations of Inferences: Sample estimates are subject to variation and should not be assumed to be exact.
Skills Covered
- Applying margin of error to estimate the population parameter range.
- Evaluating the reliability of inferences based on sample data.
- Understanding how sample size affects inference quality.
Example Problems
- A factory inspects 200 socks and finds that 8% are defective, with a margin of error of ±2%. Determine the plausible percentage of defective socks in the entire production.
- A researcher finds that the average daily screen time for a group of 150 people is 3.2 hours, with a margin of error of ±0.5 hours. What does this suggest about the actual average screen time in the population?