SOC222H5 Lecture Notes - Lecture 5: Confidence Interval, Point Estimation, Bias Of An Estimator
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Soc222 lecture 5 - estimation of population mean and portion. Point estimate; a point estimate is a sample statistic used to estimate a population value. A newspaper story reports that 15% of a sample of randomly selected. Canadians did not have a regular medical doctor. Interval estimate; confidence intervals consist of a range of values. Between 12% and 18% of canadians did not have a regular medical doctor. Bias - an estimator is unbiased if the mean of its sampling distribution is equal to the population value of interest. Sample means and proportions are unbiased estimators (of population means and proportions). Efficiency - extent to which the sampling distribution is clustered around its mean. Larger samples have greater clustering around mean and thus more efficiency. The population mean is unknown to us, and we want to estimate the population mean. What is known is about a sample: Suppose we know population (sigma)=3 minutes.
