Final answer:
Brandon's z-score for his midterm grade is 0.67, indicating that he scored 0.67 standard deviations above the mean.
Step-by-step explanation:
To find Brandon's z-score for his math midterm grade, we use the formula for calculating z-scores which is z = (X - μ) / σ. Where:
- X is Brandon's score,
- μ is the mean score of the midterm,
- σ is the standard deviation.
Plugging in the values we have:
z = (Brandon's score - mean score) / standard deviation
z = (71 - 68) / 4.5
z = 3 / 4.5
z = 0.666...
To two decimal places, Brandon's z-score is 0.67.
This means Brandon scored 0.67 standard deviations above the mean on his exam.