Having nothing else given, an appropriate hypothesis is to assume that we have integer random variable 



    X = "the number of daily sales TVs at Best Buy" 



with random values that are uniformly distributed with the minimum value of 0 and the maximum value of 10 hours.



Then the mean average  is exactly 5 =  = , as the problem states, 

and  the condition becomes "consistent with the given part" and "self-closed".



Then the probability  P(X = 10) = .    ANSWER