Saturday, March 4, 2017

Statistical Distributions

Which one doesn't belong?

Last week, I asked my students on their homework assignment:
How are the t-distributions similar to the 𝜒² distributions?
A. The shape is right-skewed.
B. The values are non-negative.
C. The tests are only right-tailed.
D. The parameter is the number of degrees of freedom.
E. The distribution mean is the number of degrees of freedom.
Their responses were very interesting. It was a great question to get to some of the misconceptions my students had about the t-distributions.

So, this week, I decided to up the ante with this question:
Which one would you choose and why?


  1. Chi square because it is skewed
    Uniform because it has no peak and fixed width
    T because it only makes sense when centered at zero
    Normal because it has an empirical rule (actually is there something similar for uniform?)