SOLUTION: I could really use some help on this problem! A group of students at a school takes a history test. The distribution is normal with a mean of 25, and a standard deviation of 4.

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Question 1048252: I could really use some help on this problem!
A group of students at a school takes a history test. The distribution is normal with a mean of 25, and a standard deviation of 4.
(a) Everyone who scores in the top 30% of the distribution gets a certificate. What is the lowest score someone can get and still earn a certificate?
(b) The top 5% of the scores get to compete in a statewide history contest. What is the lowest score someone can get and still go onto compete with the rest of the state?
Any assistance is appreciated, thank you!
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
mean of 25, and a standard deviation of 4.
a) Use invNorm(.70) to find z = .5244
*Note: z+=+blue%28x+-+mu%29%2Fblue%28sigma%29 0r blue%28sigma%29%2Az++%2B+mu+=+x
4(.5244) + 25 = 27.0976 Round up to nearest whole number
28, the lowest score someone can get and still earn a certificate
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b) invNorm(.95) = 1.6449
4(1.6449) + 25 = x , the lowest score someone can get and still go onto compete with the rest of the state?