# Algebra II

posted by on .

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

• Algebra II - ,

The z score is the difference from the mean divided by the standard deviation FOR THE PARTICULAR CLASS THE PERSON IS IN. in Maria's case the z score is (84-78)/5 = 1.2. The higher positive z score is better relative to the class.

Now see if you can do the other parts of the question.

• Algebra II - ,

drwls, now at least three of us have answered this, all with the same answer.

• Algebra II - ,

Hi Damon. Sorry I missed the other posts. At least I wasn't "odd man out" again with my sloppy math.

• Algebra II - ,

A)a
B)b
C) c