試題詳解

23. Which of the following is not true about tbe Student's t distribution?
(A)3t has more area in tbe tails and less in the center than does the normal distribution.
(B) It is used to construct confidence intervals for the population nean when tbe population standard deviation is known.
(C) It is bell shaped and symmetricnl.
(D) As the number of degrees of freedom increases, the t distribution ap approaches the nornal distribution.
(E) None of the above.