Question 3 [25] Suppose that a mobile telecommunication company's helpline receives ve calls, on average, per minute. Required: a) Discuss the difference between the Binomial probability distribution and the Poisson probability distribution. b) How many calls does the company expect to receive in a period of 30 minutes? c) What is the probability that the company will receive at most four calls in a period of 4 minutes? d) What is the probability that the company will receive at least three calls in a period of 5 minutes ? e) What is the probability that the company will receive between six and nine calls in a period of 2 minutes? Question 4 [25] The amount of time devoted to preparing for a statistics examination by students is a normally distributed random variable with a mean of 17 hours and a standard deviation of 5 hours. Required: a) What is the amount of time below which only 15% of all students spend studying? b) What is the amount of time above which only one third of all students spend studying? c) What is the probability that a student spends between 16 and 20 hours studying? d) What is the probability that a student spends at least 15 hours studying? e) What is the probability that a student spends at most 18 hours studying