SOLUTION: The slumber for doctors is normally distributed with a mean of 6.8 hours and a standard deviation of 1.2 hours. What is the probability that in a random sample of 14 doctors, the a

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Question 868661: The slumber for doctors is normally distributed with a mean of 6.8 hours and a standard deviation of 1.2 hours. What is the probability that in a random sample of 14 doctors, the average number of slumber hours is at least 6.4?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!



Hi

z = (6.4-6.8)/1.2/sqrt(14) = -.4/.3207 = -1.2572

P(z ≥ -1.2572) = 89.57%  normalcdf(-1.2572, 100)