Question 768449
The bulbs manufactured by a company gave a mean life of 3000 hours with standard
deviation of 400 hours. If a bulb is selected at random, what is the probability it will have a mean life less than 2000 hours
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z(2000) = (2000-3000)/400 = -1000/400 = -5/2
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P(x < 2000) = P(z < -5/2) = binomcdf(-100,-5/2) = 0.0062
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Cheers,
Stan H.