Quiz

In a recent gallop poll, American adults were asked how many alcoholic beverages of any kind has they had in the last seven days.  Below are the results of the survey:

Number of Drinks                Frequency

     0                                        350

    1-7                                     490

    8-19                                   110

    20+                                      50

If this survey accurately reflects the general population, find the probability that a randomly selected adult had more than 7 alcoholic beverages in the last seven days.