6) It is known that machines that places stickers on apples miss an apple every now and then, and as a result, some apples are packaged unlabelled. It was found that a particular machine misses every twentieth apple, on average. If a box contains 100 apples, a) how many unlabelled apples would you expect to nd in such a box? b) what is the standard deviation of the number of unlabelled apples? c) what is the probability that there is at least one unlabelled apple in the box? d) Four such boxes are to be shipped. What is the probability that not more than two of them have apples without stickers