Question

a.The Road Transport and Safety Agency (RTSA), a government body, was investigating the speeds at which motorists are able to drive in Lusaka and Ndola city centres. Various news reports and recent surveys have implied that Lusaka is a much less pleasant city to drive around, and drivers in the capital spend a lot of time sitting in traffic and waiting. Using automatic monitoring cameras, speeds of 200 cars were measured (in km/h) in Lusaka: an average speed was found of 50 km/h with a standard deviation of 5 km/h. A similar sample of 200 cars in Ndola had an average speed of 58 km/h with a standard deviation of 6 km/h.

i.Determine whether the average speed of cars in Ndola is significantly higher than in Lusaka.(4 marks)

b.Lusaka Airport has two runways that operate at different levels at different times of the day. The planning director for the airport is looking at utilisation levels of the two runways and has discovered that during the Monday morning peak period of 0700-0730, on average, there were three departures from Runway 1 and four departures from Runway 2. Calculate the probability that on a particular Monday between 0700 and 0730:

i.There are more than four departures from Runway 1.(2 Marks)

ii.There are no more than three departures from Runway 2. (2 Marks)

iii.There are two departures from Runway 1 and two departures from Runway 2.(2 Marks)

TOTAL [10 MARKS]