SOLUTION: he mean of a normal probability distribution is 540; the standard deviation is 95.(Round the final answers to 2 decimal places.) a. About what percentage of the obser

Algebra ->  Probability-and-statistics -> SOLUTION: he mean of a normal probability distribution is 540; the standard deviation is 95.(Round the final answers to 2 decimal places.) a. About what percentage of the obser      Log On


   

Question 1119438: he mean of a normal probability distribution is 540; the standard deviation is 95.(Round the final answers to 2 decimal places.)

a.
About what percentage of the observations lie between 445 and 635?


Percentage of observations %

b. About what percentage of the observations lie between 350 and 730?


Percentage of observations %

c. About what percentage of the observations lie between 255 and 825?


Percentage of observations %
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The mean of a normal probability distribution is 540; the standard deviation is 95.(Round the final answers to 2 decimal places.)
a.
About what percentage of the observations lie between 445 and 635?
z(445) = (445-540)/95 = -1
z(635) = (635-540)/95 = +1
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P(445<= x <=635) = P(-1<= z <=1) = 0.6827 = 68.25%
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b. About what percentage of the observations lie between 350 and 730?
Use the same procedure.
Ans:: 95.45%
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c. About what percentage of the observations lie between 255 and 825?
Use the same procedure.
Ans:: 99.73%
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Cheers,
Stan H.
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