A sample of 49 observations is selected from a normal population. The sample mean is 61, and the population standard deviation is 6. Conduct the following test of hypothesis using the 0.10 significance level. Hg: H = 63 a. Is this a one- or two-tailed test? O One-tailed test O Two-tailed test b. What is the decision rule? O Reject H, if -1.645 < z< 1.645 O Reject H, if z<-1.645 or z>1.645 c. What is the value of the test statistic? (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.) Value of the test statistic d. What is your decision regarding Hg? O Fail to reject Hg O Reiect Ha

A study was done using a treatment group and a placebo group. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a 0.01 significance level for both parts. a. Test the claim that the two samples are from populations with the same mean. What are the null and alternative hypotheses? OA. Ho H1 H2 H₁: H1 H2 The test statistic, t, is -1.55. (Round to two decimal places as needed.) The P-value is (Round to three decimal places as needed.) OB. Ho: H1 H2 H₁₁₂ D. Ho: H1 H2 H₁: H1 H2 Treatment Placebo μ H₁ H2 n 25 40 X 2.38 2.65 S 0.53 0.87

A sample of 64 body temperatures has a mean of 98.6 oF. Assume that σ is known to be 0.5 oF. Use a 0.05 significance level to test the claim that the mean body temperature of the population is equal to 98.5 oF, as is commonly believed. What is the value of test statistic for this testing? -1.6 1.6 2.0 2.6