SOLUTION: Maria and Zoe are taking Biology 101 but are in different classes. Maria’s class has an average of 78% with a standard deviation of 5% on the midterm while Zoe’s class has an avera

Algebra ->  Probability-and-statistics -> SOLUTION: Maria and Zoe are taking Biology 101 but are in different classes. Maria’s class has an average of 78% with a standard deviation of 5% on the midterm while Zoe’s class has an avera      Log On


   



Question 826988: Maria and Zoe are taking Biology 101 but are in different classes. Maria’s class has an average of 78% with a standard deviation of 5% on the midterm while Zoe’s class has an average of 83% with a standard deviation of 12%. Assume that scores in both classes follow a normal distribution. Now suppose that Maria scored an 84 on the midterm exam and Zoe scored an 89.
Who did better relative to their class?
A.Maria
B.Zoe
C.Cannot Determine
D.They performed equally

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Maria and Zoe are taking Biology 101 but are in different classes.
Maria’s class has an average of 78% with a standard deviation of 5% on the midterm while
Zoe’s class has an average of 83% with a standard deviation of 12%.
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Assume that scores in both classes follow a normal distribution.
Now suppose that Maria scored an 84 on the midterm exam
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z(0.84) = (0.84-0.78)/0.05 = 1.2
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and Zoe scored an 89
z(0.89) = (0.89-0.83)/0.12 = 0.06/0.12 = 0.5
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Who did better relative to their class?
Ans: Maria's score was 1.2 std above the mean of her class.
Zoe's score was 1/2 std above the mean of her class.
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Cheers,
Stan H.
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A.Maria
B.Zoe
C.Cannot Determine
D.They performed equally