Question
the scores of a standardized test are normally distribution with a mean of 312 and a standard deviation of 68. The bottom 40% of scores are designed 'Need improvement'. What is the cutoff score for those who 'Need improvement'?
Answers
PsyDAG
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z score related to the proportion (.40). Insert values into equation above to find the score.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z score related to the proportion (.40). Insert values into equation above to find the score.