Question

2. (a) A microwave oven repairer says that the mean repair cost for damaged microwave ovens is less than RM100. You work for the repairer and want to test this claim. You find that a random sample of 5 microwave ovens has a mean repair cost RM75 and a standard deviation of RM12.50. At a =0.01, do you have enough evidence to support the repairer's claim? Assume the mean repair cost is normally distributed. (7 marks) (b) A nutritionist claims that the mean local fruit consumption by a person in Kuala Lumpur is 3.4 kg per month. A sample of 60 people in the state shows that the mean local fruit consumption by a person is 3.2 kg per month with standard deviation of 1.13 kg. At a = 0.08, can you reject the nutritionist's claim? Assume the population is normally distributed (7 marks) (C) I travel to work by route A or route B. The probability that I choose route A is 25%. The probability that I am late for work if I go via route A is 70% while the probability that I am late for work if I go via route B is 30%. Draw the tree diagram. Hence, find the probability that I am late for work. 6 marks) (CLO3:PLO4:04)

Answer 1

2) a) number of samples Std. dewahon : RM 12.50 Mean Hepcia Cost -RM75 x = RM100 a:0:01 -acceptance region 907 2 = 1.285 107. za M= RM75 for 90% and 2=0.01 Zl0:8+86 Nul Mypothesis (he): M.= RM75100 (M.): ME RM100 from z table. z: 0.8186 Z: 1.285 ZŽ - M. : 75-100 logas olun 12.5 5155 12.5/55 Z caie. 4:47 2 the Z call *<z repair ens. claim is valid since Z calc lies in acceptance Megion. ko : 3127.12

6). а: 60 х: 3: : month I month м: ч з 1-135 4:0:08 Но : 4 = 3:29 И, : и+ 3 -гч z: -1 : 75 7- 1. + 3 (чу. acceptanca region rejection region чby. от z tави . Z:1.15. 2. х- м 3. 2 - 3 - Ч 1-13 во 3 - 1:37 accept пии чbo thes м: 3:49 the nurlionist claim cannot le rejected

() 33 о: 15 хо: 3 doute бә5 Кок ontine 0:1 late о? 5x0. 7 0:25 Rout А о: 3 on time Probabili of getting late - о: 5 ¥0. 3 + oz xo: 5 - о: Ч. :чог. |