NO.PZ2015120604000130
问题如下:
We want to use z-statistic to construct confidence interval for a normally distribution. Assume the sample size is 100, sample mean is 15% and the standard deviation of sample is 25%. The significance level is supposed to be 10% , the confidence interval is :
选项:
A.
- 10.88% to 19.13%.
B.
10.88% to 19.13%.
C.
10.88% to 20.57%.
解释:
B is correct.
In this case, we can know that the Confidence Interval=[Point Estimate +/- (reliability factor)*Standard error]=
為什麼不用sample mean 15% - 10% /25%/10