Answer Happy

g) The manager is particularly concerned the chance that customers need to wait longer than 2 minutes. She summarized the waiting times of the two types of counters in the following table, use it to calculate: i) the two probabilities that a randomly selected customer of using the cashiers has waited longer than 2 minutes; ii) the probabilities that a randomly selected customer who have waited at least 2 minutes has used the self-serve counters; iii) Show whether the waiting time for the two types of counters are independent. (8 marks) Wait less than 2 Wait at least 2 No. of customers minutes minutes 87 140 131 74 218 214 Cashiers Self-serve counters Total Total 227 205 432