STAT-S 300 Lecture Notes - Lecture 19: Randomized Experiment, Statistical Parameter, Random Assignment
Document Summary
Point estimator- statistic (ie. ) that provides an estimate of a population parameter: point estimate- value of that statistic from a sample, best guess at value of unknown parameter, ideal- no bias, low variability. The idea of a confidence interval: confidence interval (ci) for parameter has 2 parts. Interval calculated from data, which has form estimate margin of error . Margin of error tells us how close the estimate tends to be to the unknown parameter in repeated random sampling. Tells how close estimator is to parameter. Confidence level c- proportion (c%) of intervals, out of all possible intervals, that capture true parameter: how to calculate a confidence interval. Ci = estimate margin of error. Ci = statistic (critical value)(standard error) For sample means- ci = (z*) For sample proportions- ci = (z*: critical value (z* = z critical)- number of standard deviations from mean (z-score of boundaries of confidence interval) Value depends on confidence level: interpreting ci and cl.
