If a student scored 75 points on a test where the mean score was 83.5 and the standard deviation was 3.1. The student's z score is ________.
Z = (score-mean)/SD
Insert values and calculate.
0.88
0.23
To find the z-score, we need to use the formula:
z = (x - μ) / σ
Where:
- x is the student's score (75)
- μ is the mean score (83.5)
- σ is the standard deviation (3.1)
Now, let's substitute the values into the formula:
z = (75 - 83.5) / 3.1
Simplifying this expression:
z = -8.5 / 3.1
Calculating the result:
z ≈ -2.74
Therefore, the student's z-score is approximately -2.74.