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HYPOTHESIS TESTING

The use of sample data to make a decision either to accept or to reject a statement about a parameter value or about a population distribution

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Procedure for Hypothesis Testing

Establish the hypotheses; Obtain the sample results; Choose the test statistic, set the significance level,

and look up the critical values of z or t; Calculate the standard error; Calculate the test statistic; Decide whether to reject the null hypothesis; and Take action.

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Example

A manufacturer of cereal wants to test the performance of one of its filling machines. The machine is designed to discharge a mean amount of 12 ounces per box, and the manufacturer wants to detect any departure from this setting. This quality control study calls for sampling 100 boxes to determine whether the machine is performing to specifications. The sample resulted in a mean amount of 11.85 ounces per box with a standard deviation of 0.5. Setup a test of hypothesis for this study, using = 0.01.

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Formulation of Hypotheses

Null Hypothesis: H0

The Null Hypothesis is

usually the hypothesis

that the researcher wants

to gather evidence against.

Alternative Hypothesis: HAA

The Alternative Hypothesis

is usually the hypothesis

for which the researcher

wants to gather supportive

evidence.