To find out the location measures and dispersion measures.

Nielson Monitor-Plus, a service of Nielsen Media Research, is one of the leaders in advertising information services in the United States, providing advertising activity for 16 media, including television tracking, in all 210  Designated Market Areas (DMAs).  One of the issues it has researched is the increasing amount of "clutter" - non-program minutes  in an hour of prime time - including network and local commercials and advertisements for other shows.  In 2004, the average non-programming minutes in an hour of prime-time broadcasting for network TV was 15:48 minutes.  For cable TV, the average was 14:55 minutes.

a)  Work out the difference in the average "clutter" between network and TV.

b)  Assume the standard deviation in the amount of "clutter" for both the network and cable TV was either 5 minutes or 15 seconds.  Which standard deviation would lead you to end that there was a major difference in the two "clutter" averages?  Comment.