AP Statistics
posted by Peter .
Maria and Zoe are taking Biology 105 but are in different classes. Maria's class has an average of 78% with a standard deviation of 5% on the midterm, whereas Zoe's class has an average of 83% with a standard deviation of 12%. Assume that scores in both classes follow a normal distribution.
A. Convert Maria's midterm score of 84 to a standard z score.
which is correct?
a. 0.083
b. 0.5
c. 0.2
d. 1.2
e. 6
B Convert Zoe's midterm score of 89 to a standard z score.
a. 1.2
b. 0.5
c. 6
d. 0.917
e. 2.2
C. Who did better relative to her class?
a. Maria
b. Zoe
c. They performed the same.
d. Neither
e. Cannot determine

This question was answered after it was reposted later

Maria's Zscore was 1.2
Zoe's Zscore was .5
Since a Zscore of .5 is closer to 0 (the mean) it means she scored higher than Zoe.
2 reasons behind it... the class avg was higher in Zoe's class, plus the standard deviation was more than double (it was 12 vs Maria's 5)