Concept explainers
In Exercises 7-10, compute
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- In a study of the effects of mediation on anxiety, participants were randomly assigned to either engage in a mindfulness meditation session for 5 minutes or to sit quietly for 5 minutes. All participants then completed an anxiety measure. The researchers predicted that there would be a difference in anxiety scores between the two groups. Which would be the appropriate null hypothesis? a. H0: u 1 > u 2 b. H0: u 1 = u 2 c. H0: u 1 < u 2 d. H0: u 1 > u 2arrow_forwardThe results of a hypothesis test are reported as follows in a scientific report: t(17) = +2.76, p< .05. Based on this information, which statement below is not correct? Select one: a. The sample size is n = 18. b. The sample mean is greater than the hypothesized population mean. c. The conclusion reached by the researcher was to reject the null hypothesis. d. The probability that there is a statistically significant effect is less than 5%.arrow_forwardIf, in a sample of n=20 selected from a normal population, X=59and S=12, what are the critical values of t if the level of significance, α, is 0.05, the null hypothesis, H0, is μ=50, and the alternative hypothesis, H1, is μ≠50? The critical values of t arearrow_forward
- e? what is the state alternative hypothesis?arrow_forwardWhat is the value of t testing the null hypothesis that the population mean is 0? Y -2 1 3 2 -1 0 4 6arrow_forwardIn a study of a group of women science majors who remained in their profession and a group who left their profession within a few months of graduation, the researchers collected the data shown here on a self-esteem questionnaire. Leavers Stayers1 = 3.05 2 = 2.92σ1 = 0.71 σ2 = 0.71n1 = 100 n2 = 227At α = 0.05, can it be concluded that there is a difference in the self-esteem scores of the two groups? Use the P-value method.arrow_forward
- To establish the alternative hypothesis, a theory that directly contradicts the research hypothesis is called. a.Statistical hypothesis b.Null hypothesis c.Alternative hypothesis d.None of thesearrow_forwardBenson Manufacturing is considering ordering electronic components from three different suppliers. The suppliers may differ in terms of quality in that the proportion or percentage of defective components may differ among the suppliers. To evaluate the proportion of defective components for the suppliers, Benson has requested a sample shipment of 500 components from each supplier. The number of defective components and the number of good components found in each shipment are as follows. Component Supplier A B C Defective 13 18 38 Good 487 482 462 (a) Formulate the hypotheses that can be used to test for equal proportions of defective components provided by the three suppliers. H0: pA = pB = pCHa: Not all population proportions are equal.H0: All population proportions are not equal.Ha: pA = pB = pC H0: pA = pB = pCHa: All population proportions are not equal.H0: Not all population proportions are equal.Ha: pA = pB = pC (b) Using a 0.05 level of significance,…arrow_forwardBenson Manufacturing is considering ordering electronic components from three different suppliers. The suppliers may differ in terms of quality in that the proportion or percentage of defective components may differ among the suppliers. To evaluate the proportion of defective components for the suppliers, Benson has requested a sample shipment of 500 components from each supplier. The number of defective components and the number of good components found in each shipment are as follows. Component Supplier A B C Defective 13 18 38 Good 487 482 462 (a) Formulate the hypotheses that can be used to test for equal proportions of defective components provided by the three suppliers. H0: Not all population proportions are equal.Ha: pA = pB = pCH0: All population proportions are not equal.Ha: pA = pB = pC H0: pA = pB = pCHa: Not all population proportions are equal.H0: pA = pB = pCHa: All population proportions are not equal. (b) Using a 0.05 level of significance,…arrow_forward
- 1. Suppose a researcher wants to test whether the proportion of people that reflect a certain characteristic in a population, population A, is lower than the proportion of people with that characteristic in another population, population B. The researcher plans to perform a two-sample z‑test for two proportions, testing the null hypothesis, ?0:?A−?B≥0, against the alternative hypothesis, ?1:?A−?B<0, where ?A and ?B represent the proportions of people reflecting the characteristic of interest in population A and population B, respectively. The population size exceeds 5000 in population A and in population B. The researcher selects a simple random sample from each population and records the proportion of people in each sample that reflect the characteristic of interest. The sample results are summarized in the table. Population Sample size Sample proportion A ?A=44 ?̂A=0.6364 B ?B=70 ?̂B=0.7714 Given that the samples were randomly selected from large populations and the…arrow_forwardBenson Manufacturing is considering ordering electronic components from three different suppliers. The suppliers may differ in terms of quality in that the proportion or percentage of defective components may differ among the suppliers. To evaluate the proportion of defective components for the suppliers, Benson has requested a sample shipment of 500 components from each supplier. The number of defective components and the number of good components found in each shipment are as follows. Component Supplier A B C Defective 20 25 45 Good 480 475 455 1)Formulate the hypotheses that can be used to test for equal proportions of defective components provided by the three suppliers. A) H0: All population proportions are not equal. Ha: pA = pB = pC B) H0: Not all population proportions are equal. Ha: pA = pB = pC C) H0: pA = pB = pC Ha: Not all population proportions are equal. D) H0: pA = pB = pC Ha: All population proportions are not equal. 2)Using a 0.05 level of…arrow_forwardFor a one-tailed hypothesis test with α = .01 and a sample of n= 28 scores, the critical t value is either t = +2.473 or t= -2.473. True or Falsearrow_forward
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