SOLUTION: The results of a departmental math final exam at a local college showed the scores were normally distributed with a mean score of 40 points and a standard deviation of 20 point.
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Question 929386: The results of a departmental math final exam at a local college showed the scores were normally distributed with a mean score of 40 points and a standard deviation of 20 point.
1.) What percentage of students scored over 60 points
2.) What percentage of students scored between 30 points and 50 points?
3.) What percentage of students scored below 10 points? Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website! mean = 40 , SD = 20 ,
P(x > 60) = P(z > 20/20)= normalcdf(1,100) = .1587 0r 15.87%
P(30 < x < 50) = P(-10/20 < z < 10/20) = normalcdf(-1,1) = .6827 0r 68.27%
P(x < 10) = P(z < -30/20) = normalcdf(-100, -3/2) = .0668 0r 6.68%
