SOLUTION: Help, The diameters of grapefruits in a certain orchard are normally distributed with a mean of 7.30 inches and a standard deviation of 0.80 inches. (A) What percentage of th

Algebra ->  Probability-and-statistics -> SOLUTION: Help, The diameters of grapefruits in a certain orchard are normally distributed with a mean of 7.30 inches and a standard deviation of 0.80 inches. (A) What percentage of th      Log On


   



Question 636271: Help,
The diameters of grapefruits in a certain orchard are normally distributed with a mean of 7.30 inches and a standard deviation of 0.80 inches.
(A) What percentage of the grapefruits in this orchard have diameters less than 6.7 inches?
(B) What percentage of the grapefruits in this orchard are larger than 7.20 inches?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The diameters of grapefruits in a certain orchard are normally distributed with a mean of 7.30 inches and a standard deviation of 0.80 inches.
(A) What percentage of the grapefruits in this orchard have diameters less than 6.7 inches?
z(6.7) = (6.7-7.3)/0.8 = -0.75
P(x < 6.7) = P(z<-0.75) = normalcdf(-100,-0.75) = 0.2266
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(B) What percentage of the grapefruits in this orchard are larger than 7.20 inches?
Find the z-score of 7.20
Find the probability z is greater than that z-score.
Ans: 0.5497
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Cheers,
Stan H.