Final answer:
Greg's z-score is calculated by subtracting the mean grade from his grade and dividing by the standard deviation. His z-score is 1.2, indicating he scored 1.2 standard deviations above the mean.
Step-by-step explanation:
The student's question pertains to finding the z-score for Greg's math midterm grade, which is a concept in statistics within the field of Mathematics. Given that the grades are normally distributed with a mean of 67% and a standard deviation of 2.5, and Greg scored 70%, we can calculate his z-score using the formula:
z = (X - μ) / σ
Where:
X = Greg's score (70%)
μ = Mean (67%)
σ = Standard deviation (2.5)
Substituting the given values:
z = (70 - 67) / 2.5
z = 3 / 2.5
z = 1.2
Therefore, Greg's z-score is 1.2, which means he scored 1.2 standard deviations above the mean.