What Parametric tests is
Parametric tests are a class of statistical tests used to analyze data from a population with a known underlying probability distribution. They are used to make decisions about the population parameters such as the mean, variance, and correlation. Parametric tests assume that the data follows a certain distribution, such as the normal distribution, and use the calculated parameters to make inferences about the population.
Steps for parametric tests:
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Establish the hypothesis: The first step is to state the null hypothesis and the alternate hypothesis. The null hypothesis is the statement that there is no difference between the two populations or sample groups.
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Identify the population or sample: The next step is to identify the population or sample that will be used in the parametric test. This can be done by randomly selecting individuals from the population or sample.
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Select the parametric test: Once the population or sample has been identified, the appropriate parametric test can be selected. There are a variety of parametric tests available, and each is best suited for a particular type of data.
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Calculate the test statistic: The test statistic is the numerical value that is used to compare the two populations or samples. It is calculated using the data from the population or sample.
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Compare the test statistic to the critical value: The test statistic is then compared to the critical value. This is the value that is used to reject or accept the null hypothesis.
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Make a decision: After comparing the test statistic to the critical value, a decision is made about whether to reject or accept the null hypothesis.
Examples
- Comparing means of two or more groups to determine if a significant difference exists.
- Testing the hypothesis that two or more population variances are equal.
- Testing the hypothesis that two or more population correlation coefficients are equal.
- Determining the significance of the difference between two or more proportions.
- Testing the hypothesis that two or more population regression lines are equal.