The College Board states that the average math SAT score is 514 with a standard deviation of 117. Colleen gathered data from 50 students in her graduating class and found the average score to be 529. She thinks that her class’s math SAT score is different from the average. Which of the following shows the correct z-statistic for this situation?
a.0.38
b.0.91
c.1.26
d.5.67

Question

The College Board states that the average math SAT score is 514 with a standard deviation of 117. Colleen gathered data from 50 students in her graduating class and found the average score to be 529. She thinks that her class’s math SAT score is different from the average. Which of the following shows the correct z-statistic for this situation?
a.0.38
b.0.91
c.1.26
d.5.67

marihelenh · Answer

z-score= (your value - mean) / st. dev.

anonymous · Answer

i have tried to do it and i don't understand

marihelenh · Answer

Your value is 529.
The mean is 514.
The st. dev. is 117.

Subtract the first two. Then divide by the st. dev.

marihelenh · Answer

You know what, I think I read it wrong, just a minute.

marihelenh · Answer

I'm pretty sure I am right, although I don't understand why my answer doesn't match up.

anonymous · Answer

i got b is that correct

marihelenh · Answer

I don't know. My answer is different, so you can wait up for someone else, or go with your gut. It appears you have been doing well so far.