Interview Question: Normal Division

Sample Question #64 (probability theory)

If random variable X is normally distributed, is X/k, where k is a known constant, also normal? Why or why not? Please "prove"  your answer using the pdf.

(Comment: this question is an example where just memorizing properties you learned in textbooks is not sufficient. You must understand the why’s in addition to the what’s – just like in science!)

Advertisements
This entry was posted in Sample Qs. Bookmark the permalink.

One Response to Interview Question: Normal Division

  1. Brett says:

    ANSWER
     
    First you should realize that the question only makes sense if k is not 0. Whenever you see a division problem, always check whether the denominator can be 0.
     
    Otherwise, the pdf just undergoes a scalar transformation, which means X/k is also a normal random variable.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s