Question

A study looking at symptoms and care-seeking behavior in African-American patients with chest pain, measured the systolic blood pressure of 157 African-American men seen in an emergency department. The mean systolic blood pressure was 146 mm Hg with a standard deviation of 27. The researchers wish to know if on the basis of these data, they can conclude that the mean systolic blood pressure is greater than 140. Use α=.05. Give each of the following to receive full credit: 1) the appropriate null and alternative hypotheses; 2) the appropriate test; 3) the decision rule; 4) the calculation of the test statistic; and 5) your conclusion including a comparison to alpha or the critical value. You MUST show your work to receive full credit. Partial credit is available. [PLEASE BE AS DETAILED AS POSSIBLE, I REALLY DON'T GET THIS AND NONE OF THE ONLINE HELP SHOWED THE STEPS]

Answer 1

Answer Date: 20/02/2018 1 and 2) To test the hypothesis is that the mean systolic blood pressure is greater than 140 at 5% significance level and t-hypothesis test apply due to the population standard deviation unknown and normal distribution follow The null and alternative hypothesis is, Ha u>140 3) The t-critical value is, The sample size is small and right-tailed test. Look in the column headed α the row headed in the t distribution tableby using degree of freedom is, 0.05 and - 157-1 - 156

The f-critical vałue is [1.655. The decision rule is, If the t 21.655 , then the test statistics values of t is falls in the critical region as result reject the null hypothesis. If the t s1.655, then the test statistics values of t is not falls in the critical region as result fail to reject the null hypothesis. 4) The t-test statistics is, 146 -140 27/v157 -2.78 The f-test statistics is 2.78

5) Decision The statistical decision is that the t-test statistics which is 2.78 is higher than t-critical value which is 1.655, so the null hypothesis is rejected at 5% level of significance. There is sufficient evidence to indicate that the mean systolic blood pressure is greater than 140 The result is statistically significant