Which statement correctly compares t-distributions to the normal distribution?
I. t distributions are also mound shaped and symmetric.
II. t distributions have less spread than the normal distribution.
III. As degrees of freedom increase, the variance of t distributions becomes smaller.
A) I, II, and III
B) I only
C) I and III only
D) I and II only
E) II only

Question

Quizplus · Accepted Answer

t-distributions are mound-shaped and symmetric like the normal distribution (I). As degrees of freedom increase, the variance of t-distributions decreases, approaching the normal distribution (III). However, t-distributions have more spread than the normal distribution, not less (II is incorrect).

Which Statement Correctly Compares T-Distributions to the Normal Distribution