A-level FURTHER MATHEMATICS Paper 3 Statistics

Answer all questions in the spaces provided. 1 The discrete random variable A takes only the values 0, 2 and 4, and has cumulative distribution function F(a) ¼ P(A ≤ a) box a 0 2 4 F(a) 0.2 0.6 1 Find P(A ¼ 2) Circle your answer. [1 mark] 0 0.4 0.6 0.8 2 The time, T days, between rain showers in a city in autumn can be modelled by an exponential distribution with mean 1.25 Find the distribution of the number of rain showers per day in the city. Tick (3) one box. [1 mark] Distribution Mean Exponential 0.8 Turn over 3 The masses of tins of a particular brand of spaghetti are normally distributed with mean m grams and standard deviation 4.1 grams. A random sample of 11 tins of spaghetti has a mean mass of 401.8 grams. Construct a 98% confidence interval for m, giving your values to one decimal place. [3 marks]