Question 1
An airline knows from experience that the distribution of the number of suitcases that get lost each
week on a certain route is approximately normal with µ = 15.5 and s = 3.6. During a given week:
1.1. What is the probability that the airline will lose less than 10 suitcases? (6)
1.2. What is the probability that the airline will lose between 10 and 20 suitcases? (8)
1.3. What is the probability that the airline will lose more than 20 suitcases? (8)
[22 marks]
Question 2
According to the department of Labour, the average weekly pay for a South African production
worker was R441.84 in 2010. Assume that available data indicate that wages are normally distributed
with standard deviation of R90.00
2.1. What is the probability that a South African production worker earns between R400.00 and
R500.00? (8)
2.2. How much does a South African production worker have to make to be in the in the top 20% of
wage earners? (8)
2.3. For a randomly selected production worker, what is the probability the South African worker
earns less than R250.00 per week?
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