For smaller samples, the t distributions are wider and flatter than the z distributions.

Question

Quizplus · Accepted Answer

This is because t distributions take into account the uncertainty in estimating the population standard deviation, which is greater for smaller sample sizes, and therefore results in wider and flatter distributions. Z distributions, on the other hand, assume that the population standard deviation is known and fixed, resulting in narrower and taller distributions.

For Smaller Samples, the T Distributions Are Wider and Flatter