NO.PZ2015120604000145
问题如下:
Here is a table discribing sample statistics from two bonds' rate of return which are both normally distributed over the past decades. If an investor is considering whether the mean of bond A is equal to 22%,
which of the following conclusion is least appropriate (significant level=1%) ?
选项:
A.
The null hypothesis can be rejected.
B.
It is appropriate to use a two-tailed t-test.
C.
The test statistic value is 1.333.
解释:
A is correct.
The null hypothesis:
Because the sample size is 25, which is less than 30, so it is appropriate to use the two-tailed t-test.
t at α= 0.01= ±2.797;
Because -2.797 <1.333<+2.797, therefore, H0 cannot be rejected.
不是已知方差用的是Z吗