Question 542853
A new headache remedy has been found to begin causing relief from headaches with a normal distribution with a mean of 25 minutes and standard deviation of 8 minutes. 
If a headache sufferer takes this medication, what is the probability that she will feel relief in 30 minutes or less?
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z(30) = (30-25)/8 = 5/8
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P(x <= 30) = P(z <= 5/8) = 0.2660
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Cheers,
Stan H.