STATISTICS 3N03
Instructions
Aids permitted: any calculators, any tables and one sheet of notes (8.5" x 11", one side only). If the tables are in a textbook, elastic bands must be drawn around the remaining pages so that only the tables can be used.
(b) Give one example of a pivotal quantity, and write out the confidence interval formula derived from it. [5 marks]
(b) What applied problem motivated Gosset to study the Poisson distribution? [2 marks]
(c) What two professions claim Florence Nightingale as a pioneer? [1 mark]
(a) Ten tires of Brand A and 8 tires of Brand B were road-tested to determine tread life in units of 100 km.
Brand A: 61.1 58.2 62.3 64.0 59.7 66.2 57.8 61.4 62.2 63.6 Brand B: 62.2 56.6 66.4 56.2 57.4 58.4 57.6 65.4
(b) An industrial safety program was instituted in 10 similar factories. The number of employee hours lost due to accidents per week (averaged over one month) was recorded at each plant before and after the program. The factories are listed in no particular order.
Factory 1 2 3 4 5 6 7 8 9 10 Before 30.5 18.5 24.5 32.0 16.0 15.0 23.5 25.5 28.0 18.0 After 23.0 21.0 22.0 28.5 14.5 15.5 24.5 21.0 23.5 16.5