“the national occupant protection use survey (nopus) is the only probability-based survey of driver cell phone use in the united states. the survey observes usage as it actually occurs at a random selection of roadway sites, and so provides the best tracking of the extent to which people in this country are using cell phones while driving.” nopus observed 43,000 drivers in this study. which question is this observational study designed to answer?

I believe the answer is: What proportion of U.S. drivers talk on a cell phone while driving?

This purpose could be seen in this part of the description: survey observes usage as it actually occurs at a random selection of roadway. The researchers would most lilkely try to find the correlation between the number of drivers who talk at the cell phone while driving with an undesired event, such as accidents.

it looks like its all of the above. [.wpal1kojopfdpojfrfionrnif.knfdsnksjosjo]

explanation:

you have to combine all of your answers together to

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well considering i can't see the graph, it's probably prices