Which statement correctly compares t-distributions to the normal distribution?

I. t-distributions are also unimodal, mound shaped and symmetric.

II. t-distributions have more spread than the normal distribution.

III. As degrees of freedom decrease, the variance of t-distribtuions becomes smaller.

1. II only

2. I and II only

3. I only

4. I and III only

III is not correct. With more degrees of freedom (really estimates of mean with more samples) its variance decreases.

II is true - the t-distribution has larger tails than the normal distribution and its peak is smaller.

I is also true - the t-distribution is symmertic, mound shaped and unimodal (have one maximum)

so 2 it is.

Secure Information

Content will be erased after question is completed.

Enter the email address associated with your account, and we will email you a link to reset your password.

Forgot your password?

Sign Up