A student scored 84 points on a test where the mean score was 79 and the standard deviation was 4. Find the student's z score, rounded to 2 decimal places
1.25
64.25
To find the student's z score, which measures how many standard deviations away from the mean the student's score is, we can use the formula:
z = (x - μ) / σ
Where:
- x is the student's score
- μ is the mean score
- σ is the standard deviation
In this case, we know that:
- x (the student's score) is 84
- μ (the mean score) is 79
- σ (the standard deviation) is 4
Plugging these values into the formula, we get:
z = (84 - 79) / 4
Calculating this, we find:
z = 5 / 4
Dividing 5 by 4, we get:
z = 1.25
To round the z score to two decimal places, we round 1.25 to:
z ≈ 1.25
Therefore, the student's z score is approximately 1.25.
Use z-score formula.
z = (x - mean)/sd
x = 84
mean = 79
sd = 4
Plug the values into the formula and calculate for your z-score.