W1 Understanding the Hypothesis One Sample

W1 Understanding the Hypothesis One Sample - the other half...

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Understanding the Hypothesis – One Sample Class, the hypothesis is an idea, an assumption that something is true. There is no correlation between two things. In hypothesis testing (at this point) we are testing one sample out of a population to see if it is within 95% of all the data in the population (if we choose a level of significance, for example, of 0.05 or 5%). If our level of significance (los) is 0.05, that says we believe that our sample will likely be in the 95% of the normal distribution curve (95% + 0.05% = 100% of the normal distribution curve). Remember also from RES341, when we have a population of data, we know that according to the Empirical Rule, 68% of the data will be within 1 standard deviation of the population mean (mu), 98% within 2 standard deviations, and 99% within 3 standard deviations. To try and sum this up, when we have a population of data (such as 30 or more data points), half of these data points will be on one side (+) of the population mean (mu), and
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Unformatted text preview: the other half distributed on the other side (-). With an los of 0.05 we know that some of the data is going to be beyond 95% of the data (with a level of significance of 0.05 or 5%). So we test one of the 30+ samples (in our example) to see if it is within 95% of the range of the distribution. If it is within that 95% then we accept the null, if outside that range, we reject the null. What we have not totally covered is the decision rule (DR). The DR is always based on the critical value (the point where the null is rejected), and this critical value is related to the level of significance we choose. All of this discussion here may still leave you with some uncertainty, so I encourage you to return to the e-book and slowly "walk through" the assigned Chapter 9 readings. The visuals of the distribution curve and the critical value points may help....
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This note was uploaded on 10/10/2010 for the course STATS Stats301 taught by Professor Regis during the Spring '10 term at DeVry Irvine.

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