Hypothesis Testing Essay

1784 Words Apr 27th, 2013 8 Pages
Hypothesis Testing

Hypothesis testing is basically a process that uses statistical inference to test claims about population parameters. In hypothesis testing we begin by making a tentative assumption about a population parameter. This assumption is called the null hypothesis and is denoted by Ho. We then define another hypothesis, called the alternative hypothesis, which is the opposite of what is stated is the null hypothesis. The alternative hypothesis is denoted by Ha. The hypothesis testing procedure involves using data from a sample to test the competing claims indicated by the null and alternate hypotheses.

Testing the hypothesis is similar to a criminal trail. Ho: The defendant is innocent Ha: The
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In order to evaluate the new design, several new carburetors will be manufactured, installed in automobiles, and subjected to research controlled driving tests. Notice that the product research group is looking for evidence to conclude that the new design increases the miles per gallon. In this case the research hypothesis is that the new carburetor will provide a mean miles per gallon exceeding 25; that is, [pic]. As a general guideline, a research hypothesis such as this is formulated as the alternative hypothesis. Thus appropriate null and alternative hypotheses for this study are as follows: Ho: [pic]< 25 Ha: [pic]> 25
If the sample results indicate that Ho cannot be rejected, we will not conclude that the carburetor improves mileage. Perhaps more research and testing needs to be conducted. If the sample data suggests that the null hypothesis can be rejected, the inference is made that [pic]> 25 since the researcher now has the necessary statistical support.
In research studies such as these, the null and alternate hypotheses should be formulated so that the rejection of the null, and hence the inference that the alternative is true, will provide the researcher with the conclusion and action being sought. The research hypothesis then should be expressed as the alternative hypothesis.

Testing Validity of Assumption

Testing Validity of

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