SOLUTION: The distribution of weights in a large group is approximately normally distributed. The mean is 80 kg and approximately 69% of the weights are between 70 and 90 kg. The standard de
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Question 851666: The distribution of weights in a large group is approximately normally distributed. The mean is 80 kg and approximately 69% of the weights are between 70 and 90 kg. The standard deviation of the distribution of weights is equal to:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The distribution of weights in a large group is approximately normally distributed. The mean is 80 kg and approximately 69% of the weights are between 70 and 90 kg. The standard deviation of the distribution of weights is equal to:
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Find the z-values that bracket 69% of the data around the mean.
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Find the z-value with a left tail of (0.5-(0.69/2)) = 0.155
invNorm(0.155) = -1.0152)
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Use x = z*s + u to solve for "s"
70 = -1.0152s + 80
1.0152s = 10
s = 9.85..
Cheers,
Stan H.
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