Section 8.1: Basic Properties of Confidence Intervals
- Determine the margin of error for the sample mean from a Gaussian population with known standard deviation \(\sigma\) at a confidence level \(c\).
- Recognize the relationship between a confidence level \(c\) and tail value \(\alpha\), and state how these specify the probability in the tails or body of a given distribution.
- Determine the critical value \(z_{\alpha}\) for a standard Gaussian random variable using both Table A.3 and R’s qnorm.
- Define interval estimator and confidence interval, and make an analogy between them and point estimators and point estimates.
- Construct a \(c = 1 - \alpha\) confidence interval for a population mean \(\mu\) using a random sample from a Gaussian population when the population standard deviation \(\sigma\) is known.
- Sketch the confidence interval from the previous learning objective.
Section 8.3: Intervals Based on a Normal Population Distribution
- Give a constructive definition of a \(t\)-distributed random variable \(T\) using a random sample from a Gaussian population.
- Determine the parameter of a \(t\)-distributed random variable \(T\) constructed using a random sample from a Gaussian population.
- Describe the general properties of the probability density function of a \(t\)-distributed random variable as compared to a standard Gaussian random variable including where each is centered, the symmetry properties of each, and the “fatness” of the tails of each.
- Determine the critical value \(t_{\alpha, \nu}\) for a random variable \(T\) that is \(t\)-distributed with parameter \(\nu\) using both Table A.5 and R’s qt.
- Construct a \(c = 1 - \alpha\) confidence interval for a population mean \(\mu\) using a random sample from a Gaussian population when the population standard deviation \(\sigma\) is unknown.
- Sketch the confidence interval from the previous learning objective.
- Reason about what confidence interval we have covered, if any, is appropriate for the population mean given a description of a sample from that population.