Question 632207
Each month, an American household generates an average of 28 pounds of newspaper
for garbage or recyling with a standard deviation of 2 pounds. Assuming a normal
distribution, what percentage of American households generate between 27.8 and 31.3 pounds per month?
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z(27.8) = (27.8-28)/2 = -0.1
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z(31.3) = (31.3-28)/2 = 3.3/2 = 1.65
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P(27.8<= x <=31.3) = P(-0.1<= z <=1.65) = 0.4904
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Cheers,
Stan H.
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