A researcher is evaluating the influence of a treatment using a sample selected from a normally distributed population with a mean of u = 40 and a standard deviation of o = 12 . The researcher expects a 6-point treatment effect and plans to use a two-tailed hypothesis test with a = .05 . a. Compute the power of the test if the researcher uses a sample of n = 9 individuals. (See Example 8.6.) b. Compute the power of the test if the researcher uses a sample of n = 16 individuals.

A researcher was doing a study for a new Coronavirus Drug and conducted a hypothesis test like this one: H0: μ = 18 Ha: μ ≠ 18 a.  What type of test is this?   left-tailed right-tailed two-tailed   b. She obtained a test statistic of 0.75, with a p-value of 0.4648.  So she concluded that her true mean must be equal to 18.   Is this interpretation correct?  Yes No Why or why not?

A researcher expects a treatment to produce an increase in the population mean. The treatment is evaluated using a one tailed hypothesis test, and the test produces z = -1.85. Based on this result, what is the correct statistical decision? O The researcher should reject the null hypothesis with either a = .05 or α = .01. O The researcher should reject the null hypothesis with a = .05 but not with α = .01. O cannot answer without additional information O The researcher should fail to reject Ho with either a = .05 or α = .01.

Under what circumstances is a t statistic used instead of a z-score for a hypothesis test?     Justin wants to know whether a commonly prescribed drug does improve the attention span of students with attention deficit disorder (ADD). He knows that the mean attention span for students with ADD who are not taking the drug is 2.3 minutes long. His sample of 12 students taking the drug yielded a mean of 4.6 minutes. Justin can find no information regarding σx , so he calculated s2x =1.96. Determine the critical region using a one-tailed test with alpha = .05. Conduct the hypothesis test (Do the math and compare the t-critical and t-obtained values). State your conclusions in terms of H0 (Should you reject the H0 or fail to reject/accept the H0). Based on your analysis, is there a relationship between the drug and attention span?

Kurtis is a statistician who claims that the average salary of an employee in the city of Yarmouth is no more than $55,000 per year. Gina, his colleague, believes this to be incorrect, so she randomly selects 61 employees who work in Yarmouth and record their annual salary. Gina calculates the sample mean income to be $56,500 per year with a sample standard deviation of 3,750. Using the alternative hypothesis H1 : 55.0 appropriate hypothesis test. Round the test statistic to two decimal places and the p-value to three decimal places. Right-Tailed T-Table probability Degrees of Freedom 54 0.00040.00140.00240.00340.00440.00540.0064 56 57 58 59 60 3.562 3.135 2.943 2.816 2.719 2.641 2.576 3.558 3.132 2.941 2.814 2.7172.640 2.574 3.554 3.130 2.939 2.8122.716 2.638 2.572 3.550 3.127 2.937 2.810 2.714 2.636 2.571 3.547 3.125 2.935 2.8082.712 2.635 2.569 3.544 3.122 2.933 2.806 2.711 2.633 2.568 3.540 3.120 2.931 2.805 2.709 2.632 2.567 Provide your answer below , p-value -

A sample of 42 observations is selected from one population with a population standard deviation of 4.5. The sample mean is 100.5. A sample of 56 observations is selected from a second population with a population standard deviation of 3.8. The sample mean is 98.5. Conduct the following test of hypothesis using the 0.10 significance level. H₂ H₁ H₂ H₁ H₁ H₂ a. Is this a one-tailed or a two-tailed test? O One-tailed test O Two-tailed test b. State the decision rule. (Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.) The decision rule is to reject H0 if z is the interval (

Is psychiatric history dependent on where the mother lives (country or city)? The test statistics for this hypothesis test are.... How to run t-test? which variable goes where? I attached images, is that correct and where to get the t statistic and p-value?