In: Statistics and Probability
Q2) A worker can accomplish certain task either by A or B approaches. If approach A is followed, then the required time is normally distributed with mean 46 minutes and standard deviation 10 minutes. If approach B is followed, then the required time is normally distributed with mean μ minutes and standard deviation 12 minutes.
i. Find the value of μ if the probability that the required time less than 60 minutes is 0.85.
ii. The worker starts at 8:00 am and wants to finish before 9:00 am, which approach he should follow (Justify your answer).
given data are:-
i).according to the problem:-
[ in any blank cell of excel type =NORMSINV(0.85) ]
b).8.00 am - 9.00 am = 60 minutes.
****APPROACH A****
the probability that the worker starts at 8:00 am and wants to finish before 9:00 am ,i.e, finishes in less than 60 minutes is:-
[ using standard normal table ]
****APPROACH B****
the probability that the worker starts at 8:00 am and wants to finish before 9:00 am ,i.e, finishes in less than 60 minutes is:-
[ already given in part i ]
he should follow APPROACH A , as the probability that the worker starts at 8:00 am and wants to finish before 9:00 am is greater in approach A ( 0.9192) , than that of in approach B (0.85).
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