单选题
An analyst conducts a two - tailed test to determine whether
differences between the means of two populations exist: H
0: μ1-μ2=0
versus H
2: 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.