EXAMINATION ANALYTICAL SKILLS FOR DECISION MAKING (BUS -712B) 19TH-DEC, 2018 TIME: 3HRS C) [15 marks] i) The following table gives the figures of profits of two companies X and Y for 10years. Which of the two companies X and Y has greater consistency in profits? Year 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 Profit 700 625 725 625 650 700 650 700 600 650 X Profit 550 600 575 550 650 600 550 525 625 600 Y ii) From the prices of shares in X and Y given below, state which share is more stable in value: X: 55 54 52 53 56 58 52 50 51 49 Y: 108 107 105 105 106 107 104 103 104 101 D) [20 marks] A) The marks of the students are normally distributed. 10% got more than 75 marks and 20% got less than 40 marks. Find the mean and the standard deviation of the distribution. B) The mean and standard deviations of the wages of 6000 workers engaged in a factory are: GHC1, 200 and GHC400 respectively. Assuming the distribution to be normally distributed estimate: i) Percentage of workers getting wages above GHC1600 ii) Number of workers getting between GHC600 and 900 iii) Number of workers getting between GHC1,100 and GHC1,500 C) Assuming one in 80 births is a case of twins; calculate the probability of 2 or more births set on a day when 30 births occur. [Hint : Poisson] E) [15 marks] i) If the probability of a man aged 60 will live to be 70 is 0.65, what is the probability that out of 10 men now at 60, at least 7 will live up to 70? [Binomial) ii) The sum and the product of the mean and variance of a binomial distribution are 24 and 128. Find the distribution. Page 2 of 3