Let x represents the number of dvds sold per day:
To complete the probability distribution table, you need to add all the probabilities given and deduct that to 1 so that you can get the probability of 5-9, applying what I have said:Probability of 5-9:= 1 - (0.1875+0.4375+0.1250) = 1 – 0.75= 0.2500
But the question is not asking for the probability of 5-9, but 5 or more. So deduct the .1875 to 1 since .1875 only represents 0-4.P(X>= 5) = 1 - 0.1875 = 0.8125
