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Trials in an experiment with a polygraph include results that include cases of wrong results and cases of correct results. Use a significance level to test the claim that such polygraph results are correct less than ​% of the time. Identify the null​ hypothesis, alternative​ hypothesis, test​ statistic, P-value, conclusion about the null​ hypothesis, and final conclusion that addresses the original claim. Use the​ P-value method. Use the normal distribution as an approximation of the binomial distribution.

User Yim
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Trials in an experiment with a polygraph include 97 results that include 23 cases of wrong results and 74 cases of correct results. Use a 0.01 significance level to test the claim that such polygraph results are correct less than 80​% of the time. Identify the null​hypothesis, alternative​ hypothesis, test​ statistic, P-value, conclusion about the null​ hypothesis, and final conclusion that addresses the original claim. Use the​ P-value method. Use the normal distribution as an approximation of the binomial distribution.

The computation is shown below:

The null and alternative hypothesis is


H_0 : p = 0.80


Ha : p < 0.80


\hat p = (x)/( n) \\\\= (74)/(97)

= 0.7629

Now Test statistic = z


= \hat p - P0 / [\sqrtP0 * (1 - P0 ) / n]


= 0.7629 - 0.80 / [\sqrt(0.80 * 0.20) / 97]

= -0.91

Now

P-value = 0.1804


\alpha = 0.01


P-value > \alpha

So, it is Fail to reject the null hypothesis.

There is ample evidence to demonstrate that less than 80 percent of the time reports that these polygraph findings are accurate.

User Aayush Singla
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