PAST YEAR T9 Q21 2018/2019 SM025
(TOPIC 9 SPECIAL PROBABILITY DISTRIBUTION)
The amount of cement packed by a machine is normally distributed with mean 39.3 kg and standard deviation 0.9 kg. A bag of cement is randomly selected.
(a) Find the probability that the bag weighs more than 40 kg.
[2 marks]
(b) If the probability of the bag weighs not more than m kg is 0.95, determine the value of m.
[5 marks]
(c) A total of 5 bags of cement are chosen at random. Find the probability that at least 4 bags weigh more than 40 kg.
[4 marks]

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