Posted by Priscilla on .
On a standardized test, the distribution of scores is normal, the mean of the scores is 75, and the standard deviation is 5.8. If a student scored 83, the student's score ranks
1. below the 75th percentile
2. above the 97th percentile
3. between the 75th percentile and the 84th percentile
4. between the 84th percentile and the 97th percentile
I'm really confused about this problem but im pretty sure i would have to use the standard deviation chart.
Z = (score - mean)/SD
Z score is your score in terms of standard deviations.
You can use your chart, or you can find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score you found.