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State the conclusion of the test based on this p-value in terms of "Reject \(H_{0} "\) or "Do not reject \(H_{0} "\), if we use a \(5 \%\) significance level. p-value \(=0.0007\)

Short Answer

Expert verified
Given that the p-value of 0.0007 is less than the significance level of 5% or 0.05, we reject the null hypothesis \(H_{0}\).

Step by step solution

01

Understand Terminologies

In hypothesis testing, the null hypothesis (\(H_{0}\)) represents a statement of no effect or no difference. The p-value is the probability, under the null hypothesis about the unknown distribution, of randomly drawing a value equal to or more extreme than the one obtained by testing. The significance level, often denoted by \(α\), is a threshold pre-determined at which if the calculated p-value in the test is less than this level, we reject the null hypothesis in favor of the alternative hypothesis.
02

Comparing the P-Value with the Significance Level

In this case, the given p-value is 0.0007, and the significance level is 5% or 0.05. We determine whether to reject the null hypothesis \(H_{0}\) based on whether the p-value is less than or equal to the significance level.
03

Formulate the Conclusion

Seeing that 0.0007 is less than 0.05, we would reject the null hypothesis \(H_{0}\). However, it is important to remember that rejecting the null hypothesis does not prove the alternative hypothesis; it merely provides evidence to suggest the alternative hypothesis may be true.

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Most popular questions from this chapter

In this exercise, we see that it is possible to use counts instead of proportions in testing a categorical variable. Data 4.7 describes an experiment to investigate the effectiveness of the two drugs desipramine and lithium in the treatment of cocaine addiction. The results of the study are summarized in Table 4.14 on page \(323 .\) The comparison of lithium to the placebo is the subject of Example 4.34 . In this exercise, we test the success of desipramine against a placebo using a different statistic than that used in Example 4.34. Let \(p_{d}\) and \(p_{c}\) be the proportion of patients who relapse in the desipramine group and the control group, respectively. We are testing whether desipramine has a lower relapse rate then a placebo. (a) What are the null and alternative hypotheses? (b) From Table 4.14 we see that 20 of the 24 placebo patients relapsed, while 10 of the 24 desipramine patients relapsed. The observed difference in relapses for our sample is $$\begin{aligned}D &=\text { desipramine relapses }-\text { placebo relapses } \\\&=10-20=-10\end{aligned}$$ If we use this difference in number of relapses as our sample statistic, where will the randomization distribution be centered? Why? (c) If the null hypothesis is true (and desipramine has no effect beyond a placebo), we imagine that the 48 patients have the same relapse behavior regardless of which group they are in. We create the randomization distribution by simulating lots of random assignments of patients to the two groups and computing the difference in number of desipramine minus placebo relapses for each assignment. Describe how you could use index cards to create one simulated sample. How many cards do you need? What will you put on them? What will you do with them?

A study \(^{20}\) conducted in June 2015 examines ownership of tablet computers by US adults. A random sample of 959 people were surveyed, and we are told that 197 of the 455 men own a tablet and 235 of the 504 women own a tablet. We want to test whether the survey results provide evidence of a difference in the proportion owning a tablet between men and women. (a) State the null and alternative hypotheses, and define the parameters. (b) Give the notation and value of the sample statistic. In the sample, which group has higher tablet ownership: men or women? (c) Use StatKey or other technology to find the pvalue.

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