For its “Music 360" survey, Nielsen Co. asked teenagers and adults how each group has listened to music in the past 12 months. Nearly two- thirds of U.S. teenagers under the age of 18 say they use...

Extracted text: For its “Music 360" survey, Nielsen Co. asked teenagers and adults how each group has listened to music in the past 12 months. Nearly two- thirds of U.S. teenagers under the age of 18 say they use Google Inc's video-sharing site to listen to music and 35% of the teenagers said they use Pandora Media Inc's custom online radio service (The Wall Street Journal, August 14, 2012). Suppose 10 teenagers are selected randomly to be interviewed about how they listen to music. Answer questions 7- 10.


Extracted text: For a sample of 10 teenagers, compute the variance and standard deviation of the number of teenagers who use Pandora Media Inc.'s online radio service.