The class average on a math quiz was 74 and the standard deviation was 6.8.
Find the z-score for a test score of 82.
(82-74)/6.8 is the Z-value
To find the z-score for a test score of 82, we need to use the formula:
z = (x - μ) / σ
Where:
- z is the z-score,
- x is the individual test score,
- μ is the mean (class average),
- σ is the standard deviation.
In this case, the class average (μ) is 74 and the standard deviation (σ) is 6.8. The individual test score (x) is 82.
Plugging in the values into the formula:
z = (82 - 74) / 6.8
Calculating:
z = 8 / 6.8
z ≈ 1.18
Therefore, the z-score for a test score of 82 is approximately 1.18.