STAT151 Chapter Notes - Chapter 16: Confidence Interval

• School: University of Alberta
• Department: Statistics
• Course: STAT151
• Professor: Omar Rivasplata

Document Summary

Interval of numbers within which parameter is likely to fall. 95% confident that parameter falls within this interval = 95% of data falls within 1. 96 standard deviations from the mean. Margin of error = 1. 96 x se (standard error) We ask 2000 randomly selected people if they believed in ghosts. Create confidence interval around falls in. that we are 95% confident population proportion p. = 876/ 2000 = 0. 438 se= ^p(1 ^p) n. When building confidence intervals, check that np . For other confidence intervals, read value off of the last line of the t-table (called the critical value) Margin of error for confidence interval (increases when confidence level increases and decreases as sample size increases) In a poll of 100 canadians, 58% said they were proud of canadian health care. Build a 95% confidence interval in which the true proportion of canadians who are proud of their health care falls.