I just took my Chemistry midterm, and would like to know how to calculate my grade on the midterm with the curve.
MEAN = 8.9
STANDARD DEVIATION = 2.9
MY SCORE = 7
Thank You!
To calculate your grade on the Chemistry midterm with the curve, you need to convert your raw score (7) to a standardized score called a z-score. A z-score tells you how many standard deviations your score is above or below the mean.
To calculate the z-score, you can use the formula:
z = (X - μ) / σ
Where:
- X is your raw score (7 in this case)
- μ is the mean (8.9 in this case)
- σ is the standard deviation (2.9 in this case)
Plugging in the values:
z = (7 - 8.9) / 2.9
z ≈ -0.655
The next step is to find the corresponding percentile rank for your z-score. A percentile rank indicates the percentage of scores that fall below a particular z-score.
You can use a standard normal distribution table or a calculator to find the percentile. Based on the z-score (-0.655), you can find that it corresponds to approximately the 26th percentile.
Now, let's assume the curve increases your score by 2 standard deviations. You would add 2 standard deviations (2 * 2.9 = 5.8) to your score. So your adjusted score would be 7 + 5.8 = 12.8.
Finally, you can convert the adjusted score (12.8) back to a percentage or grade based on your grading scale.
It's important to note that each instructor or institution may have different grading policies and may curve exams differently. Therefore, it's always a good idea to consult your instructor or review the specific instructions for grading to ensure accuracy.