SOLUTION: 3a. If the standard deviation of a group of students’ test scores was calculated as 6.5 points and the mean of their distribution of scores was 75.5%, how many standard deviations

Algebra.Com
Question 46743: 3a. If the standard deviation of a group of students’ test scores was calculated as 6.5 points and the mean of their distribution of scores was 75.5%, how many standard deviations was a student’s score who scored 80%?
3b. Using the data above in question 3a, calculate the student’s standardized Z score. Use the formula:
z =X-mean/s

Answer by AnlytcPhil(1806)   (Show Source): You can put this solution on YOUR website!
3a. If the standard deviation of a group of students’ test 
scores was calculated as 6.5 points and the mean of their 
distribution of scores was 75.5%, how many standard 
deviations was a student’s score who scored 80%?

3b.  Using the data above in question 3a, calculate the 
student’s standardized Z score.  Use the formula:
                  _
		z = (x - x)/s 
                     _ 
Just plug in x = 80, x = 75.5 and s = 6.5

                z = (80 - 75.5)/6.5

                z = 0.6923076923

which means that the student scored about 0.7 of a 
standard deviation above (since it's positive) the mean.

Edwin

RELATED QUESTIONS

A group of 16 students are working together to study for a test. After the test, they... (answered by stanbon)
A teacher finds that the test scores of a group of 40 students have a mean of 75 and a... (answered by solver91311)
Test scores are normally distributed with a mean of 76 and a standard deviation of 10.... (answered by Edwin McCravy)
In an attempt to increase mathematics scores at a particular school, a twelve hour... (answered by Theo)
Is 120.5 correct? A standardized test has a mean of 600 and a standard deviation of 75.... (answered by stanbon)
A standardized test has a mean of 600 and a standard deviation of 75. If 1000 students... (answered by stanbon)
A group of high school students was surveyed about their use of various drugs, including... (answered by venugopalramana)
I have zero idea what this question is even asking me and really need some help.Thank you (answered by stanbon)
A professor gives an exam to one of their classes. Suppose the test scores were normally... (answered by reviewermath)