COMM 215 Lecture Notes - Lecture 8: Simple Random Sample, Confidence Interval, Point Estimation

• School: Concordia University
• Department: Commerce
• Course: COMM 215
• Professor: wissamnawfal

Document Summary

Comm 215 - lecture 8 - estimating single population parameters. Point estimate: single stat determined from sample, used to estimate corresponding pop. parameter. Sampling error: difference between statistic and parameter (ie population & sample) If all possible intervals of a width are computed, a percentage of these intervals ( the confidence level ) would have the true population parameters. Population parameters can be estimated based on the info provided by sample statistics. 2 cases: simple random sample drawn from normal distribution, population does not have normal dist. /dist. is not known. ***sampling dist. for x bar is assumed to be normally distributed. Measures the spread of sample means around the population means. Standard error is reduced with larger samples. It is possible to calculate the % of sample means in the interval a specific distance above & below the mean. This % tells us how likely the sample mean will be within the given interval.