Normal distributions follow the empirical rule, also called the 68-95-99.7 rule. The rule tells us that, for a normal distribution, there’s a 68% chance a data point falls within 1 standard deviation of the mean, there’s a 95% chance a data point falls within 2 standard deviations of the mean, and there’s a 99.7% chance a data point falls within 3 standard deviations of the mean.
Read MoreWith any hypothesis test, we need to state the null and alternative hypotheses, then determine the level of significance. We’ve already covered these first two steps, and now we want to learn how to calculate the test statistic, which will depend on whether we’re running a two-tail test or a one-tail test.
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