Question 1 a) The average income of a country ('Bull-a-stan') is known to be equivalent. £10,000 with standard deviation

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Question 1 A The Average Income Of A Country Bull A Stan Is Known To Be Equivalent 10 000 With Standard Deviation 1 (47.73 KiB) Viewed 88 times

Question 1 a) The average income of a country ('Bull-a-stan') is known to be equivalent. £10,000 with standard deviation £1,250. A sample of 50 workers is taken and their average income calculated. i) What is the probability distribution of this sample mean? ii) What is the probability of the sample mean being over £10,250? iii) What is the probability of the sample mean being below £9,500? iv) If the sample size were 10, why could you not use the same methods to find the answers to (1)-(iii)? b) The age of adults in Bull-a-stan was estimated by considering a sample with sample mean equal to 30, standard deviation equal to 10, and sample size equal to 40. Calculate the 99% confidence interval estimate of the true mean of age of adults in Bull-a-stan. If the sample size was 18, show and comment on how the method of calculation and confidence interval were altered.