STATS 250 Lecture Notes - Lecture 11: Confidence Interval, Standard Error, Dependent And Independent Variables

• School: U of M
• Department: Statistics
• Course: STATS 250
• Professor: Brenda Gunderson

Document Summary

Part 2: confidence interval for a difference in population proportions. 10. 3 ci module 2: confidence interval for the. We have two populations or groups from which independent samples are available, (or one population for which two groups can be formed using a categorical variable). The response variable is also categorical and we are interested in comparing the proportions for the two populations. Let p1 be the population proportion for the first population. Let p2 be the population proportion for the second population. Parameter: the difference in the population proportions p1 p2. p. Sample estimate: the difference in the sample proportions. So we have our estimate of the difference in the two population proportions, namely. To make our confidence interval, we need to know the multiplier. p . As in the case for estimating one population proportion, we assume the sample sizes are sufficiently large so the multiplier will be a z* value found from using the standard normal distribution.