SOCC31H3 Study Guide - Midterm Guide: Repeated Measures Design, Total Variation, Test Statistic
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= mean of means x_= standard deviation of the sampling distribution of means. Confidence intervals: the probability that population mean falls within range of mean values and is unknown. Standard error of the mean: x_= / n find standard error of mean first. X_= sample mean x_= standard error of the sample mean. It has become a matter of convention to use a wider, less precise confidence interval having a better probability of making an accurate or true estimate of the population mean hence 95% confidence interval. To find confidence interval at say 95%, the remaining is 5%, divide by 2 and look for that number on column c and u can find the corresponding z score to that value. Or x_= standard error of the sample mean. The precision of an estimate is determined by the margin of error obtained by multiplying the standard error by the z score representing a desired level of confidence.