Question 610020
A random sample of movie lengths in minutes is as follows:
110 95 131 257 118 153
8. Find the standard deviation.
Ans: 58.74
-------------------------------------- 
9. Are any of these movie lengths considered unusual in the sense of our textbook?
Explain. 
Sample mean = 114
2 standard deviations is the limit for "unusual":
2 standard deviations below is negative
2 standard deviations above is 114 + 2*58.74 = 231.48
---
So 257 minutes is "unusual" movie length.
===========================================
Cheers,
Stan H.
==========================

Does this differ with your intuition? Explain.
No; most movies are right around 2 hours or 120 minutes.
==========================================================
Cheers,
Stan H.
=============