题目
A random sample of twenty (n = 20) publicly-traded retailers produces a sample average price-to-earnings (P/E) ratio of 20.00 with sample standard deviation of 8.50. We are interested in testing hypothesis related to a possible population mean of 15.0. Each of the following conclusions is true EXCEPT which is FALSE?
选项
A.With 95.0% confidence, we reject a two-sided null hypothesis that the population's mean P\/E ratio is 15.0; we reject 95.0% H(0): \u03bc = 15.0
B.With 99.0% confidence, we reject a two-sided null hypothesis that the population's mean P\/E ratio is 15.0; we reject 99.0% H(0): \u03bc = 15.0
C.With 95.0% confidence, we accept a one-sided alternative hypothesis that the population's mean P\/E ratio is greater than 15.0; we accept 95.0% H(A): \u03bc > 15.0
D.With 99.0% confidence, we accept a one-sided alternative hypothesis that the population's mean P\/E ratio is greater than 15.0; we accept 99.0% H(A): \u03bc > 15.0
答案
B
解析
B is false. Because we fail to reject the two-sided null with 99.0% confidence,and therefore with 99.0% confidence we accept the null that μ = 15.0As standard error (SE) is 8.5/√20, the t-stat = (20-15)/[8.5/√20] = 2.631. B是错误的。 由于我们无法以99.0％的置信度拒绝两面零值，因此我们以99.0％的置信度接受了μ= 15.0的零值