A market researcher is interested in knowing the type of training that works best for DVD users. Thirty consumers are randomly selected from a population of known DVD owners (i.e., users). Ten are trained by giving them the DVD users manual and allowing them to read it. Another 10 users are trained from a 30-minuet DVD user training video. Another 10 users are trained from a self-paced computer tutorial. The users are then timed in their ability to setup and program the DVD by performing a series of operations. Which statistical analysis technique should be used? What is the Null hypothesis? Can the market researcher get an answer ? Why or Why not?