Z SCORE math
CJ 301
Assignment #5
Z SCORE
–Please answer each of the following questions. Also, INTERPRET your answers.
You must use the lecture for this week while working on this assignment
– Z score module – under the Learning Modules. (Also, use the Z score table).
*20 points total
YOUR NAME: _______________________________________________
 A state department of corrections has a policy whereby it accepts as correctional officers only those who score in the top 5 % of a qualifying exam. (4 points)
The mean of this test is 80.
Standard deviation is 10.
Would a person with a raw score of 95 be accepted?
(Calculate a Z score: score – mean/st.dev.= )
 Given a normal distribution of raw scores with a mean of 60 and a standard deviation of 10, what proportion of cases fall:

between a raw score of 40 and 80? (3 points)

between a raw score of 45 and 50? (3 points)
 Find the zscore corresponding to a raw score of 90 from a normal distribution with mean 60 and standard deviation 8. (2 points)
 For a normal distribution where the mean is 50 and the standard deviation is 8, what is the area :

Between the scores of 30 and 65? (2 points)
5. Assume that the distribution of a college entrance exam is normal with a mean of 500 and a standard deviation of 100. For each score below, find the equivalent Z score, the percentage of the area above the score, and the percentage of the area below the score. (3 + 3 points)
Score Z score % Area Above % Area Below
a) 375
b) 437