posted by Anonymous .
Which of the following statements is true about the t-distribution with k degrees of freedom?
i. the t-distribution is symmetric
ii. the t-distribution with k degrees of freedom has a smaller variance than the t-distribution with k+1 degrees of freedom
iii. the t-distribution has a larger variance than the standard normal (z) distribution
any one, or all three could be right but i don't know which ones are
The first and third are true. The t-distribution is symmetrical; the distribution is lower and the tails are wider than the normal distribution. I think the second one should be k-1 to make the statement true, but check my thinking on that one.
I hope this will help.