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Chapter 8 day 2 Notes Hypothesis Testing Continued. In the last lesson, we learned how to find the null and alternative hypotheses. The researcher’s next step is to design the study. The researcher selects the correct statistical test , chooses
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Chapter 8 day 2 Notes Hypothesis Testing Continued
In the last lesson, we learned how to find the null and alternative hypotheses. The researcher’s next step is to design the study. The researcher selects the correct statistical test, chooses an appropriate level of significance, and formulates a plan for conducting the study. ** Recall that the sample means vary about the population mean. Therefore the mean of the sample will not, in most cases, be exactly equal to the population mean.
We must decide whether or not the difference in sample statistic and population parameter is due to chance by thinking statistically. Statistical Test- Uses the data obtained from a sample to make a decision about whether or not the null hypothesis should be rejected. Test Value- Numerical value obtained from a statistical test.
The mean is computed for the data obtained from the sample and is compared to the population mean. Then a decision is made to reject or not reject the null hypothesis on the basis of the value obtained from the statistical test. If the difference is significant, the null hypothesis will be rejected. If it is not, then the null hypothesis will not be rejected.
Critical Value- Separates the critical region from the non-critical region Critical Region- (Shaded) Is the range of values of the test value that indicates that there is a significant difference and that the null hypothesis should be rejected
Non-Critical Region- (Not Shaded) Is the range of values of the test value that indicates that the difference is probably due to chance and that the null hypothesis should not be rejected **The critical value can be on the right or left side of the mean for a one-tailed test Its location depends on the inequality sign of the alternative hypothesis
A one-tailed test- Indicates that the null hypothesis should be rejected when the test value is in the critical region on one side of the mean.
Steps to Find the Critical Value For a one-tailed Test 1) Draw a picture 2) Subtract 0.5 – α 3) Find the closest area on the table 4) Find the z-value 5) Put the right sign (+/-) Right-tailed Positive Left-Tailed Negative
Steps to Find the Critical Value For a Two-tailed Test 1) Draw a picture 2) Subtract 0.5 – (α/2) 3) Find the closest area on the table 4) Find the z-value 5) Two z-values (One positive, one negative)