单选题
An analyst conducts a two-tailed test to determine whether differences between the means of two populations exist: H0:μ1-μ2=0 versus H2:μ1-μ2≠0. Assume that the populations are independent, normally distributed, and have unequal and unknown variances. The critical value with 50 degrees of freedom is 2. 126. The computed test statistic is t=1.753. Using a significance level of x=0.05, which of the following statements is TRUE? A. Use a t-test to reject the null hypothesis and accept the alternative hypothesis. B. Use a t-test to accept the null hypothesis and reject the alternative hypothesis. C. Use a z-test to reject the null hypothesis and accept the alternative hypothesis.
【正确答案】
B
【答案解析】The appropriate test is a t-test concerning differences between means. Because the critical value is greater than the computed t-value, the null hypothesis cannot be rejected at the 0.05 level of significance.