SOLUTION: there is a large supply of halogen light bulbs with the average life of 843 hours and the standard deviation of 72.4 hours. A random sample of 63 light bulbs is drawn, find the pro
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Question 838244: there is a large supply of halogen light bulbs with the average life of 843 hours and the standard deviation of 72.4 hours. A random sample of 63 light bulbs is drawn, find the probability that the sample average is more than 830 hours.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
there is a large supply of halogen light bulbs with the average life of 843 hours and the standard deviation of 72.4 hours. A random sample of 63 light bulbs is drawn, find the probability that the sample average is more than 830 hours.
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z(830) = (830-843)/[72.4/sqrt(63)] = -1.4252
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P(x-bar > 830) = P(z > -1.4252) = normalcdf(-1.4252,100) = 0.9229
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cheers,
Stan H.
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