In a local Walmart store, on average there are 10 customers ask staff-assistance per hour at a particular self-service checkout point. Assume the customers who ask staff-assistance are independent of each other.

• a) Denote by "X" the number of customers who ask staff-assistance at that particular self-service checkout point in a given hour. Write down the sample space (i.e., possible values) of X.
• b) What is the distribution of X? Explain your answer by showing that the assumption(s) of this distribution is (are) met. For the distribution chosen, you must state the parameter(s) as well.
• c) What is the probability that there are at least 30 customers who will ask staff-assistance in four hours?
• d) What is the probability that there are at most 5 customers who will ask staff-assistance in an hour?