NO.PZ2022071202000078
问题如下：
Question The confidence interval is most likely to be:选项：
A.wider as the sample size increases. B.wider as the point estimate increases. C.narrower as the reliability factor decreases.解释：
SolutionC is correct. A confidence interval for a parameter = Point estimate ± Reliability factor × Standard error. For example, the reliability factors for confidence intervals based on the standard normal distribution are 1.65 for 90% confidence intervals and 1.96 for 95% confidence intervals. For a given point estimate and standard error, the confidence interval will be narrower with a lower reliability factor.
A is incorrect. A larger sample size will reduce standard error making the confidence interval more narrow.
B is incorrect. The point estimate does not affect the width of the confidence interval.
样本量越大，估计越准确不是吗？那样置信区间会更宽啊。
比如90%的信心和99%的信心，99%的信心置信区间更宽啊
