自由度是否可以理解成分母？

问题如下：

Question An increase in which of the following items will most likely result in a wider confidence interval for the population mean?

选项：

A.Reliability factor

B.Sample size

C.Degrees of freedom

解释：

A is correct. An increase in the reliability factor (the degree of confidence) increases the width of the confidence interval. Increasing the sample size and increasing the degrees of freedom both shrink the confidence interval.

B is incorrect. Increasing the sample size shrinks the confidence interval.

C is incorrect. Increasing the degrees of freedom shrinks the confidence interval.