1. The problem involves analyzing and comparing test scores from two different classes, 2009 and 2010. 2. We want to understand the distribution and possibly calculate some statistics like mean or median for each class. 3. For each class, the mean (average) score is calculated by summing all scores and dividing by the number of scores: $$\text{Mean} = \frac{\text{Sum of all scores}}{\text{Number of scores}}$$ 4. Calculate the mean for the 2009 class: Sum of 2009 scores = $9 + 8 + 8 + 8 + 7 + 6 + 6 + 6 + 6 + 8 + 5 + 5 + 3 + 3 + 3 + 2 + 2 + 0 + 0 + 5 + 1 = 98$ Number of scores = 21 $$\text{Mean}_{2009} = \frac{98}{21} = \frac{\cancel{98}}{\cancel{21}} = 4.6667$$ 5. Calculate the mean for the 2010 class: Sum of 2010 scores = $0 + 0 + 0 + 1 + 2 + 4 + 4 + 4 + 4 + 5 + 6 + 6 + 7 + 8 + 9 + 0 + 1 + 2 + 2 + 2 + 3 + 4 + 5 + 5 + 6 + 7 + 3 + 8 + 0 = 104$ Number of scores = 29 $$\text{Mean}_{2010} = \frac{104}{29} = 3.5862$$ 6. Interpretation: The 2009 class has a higher average score ($4.67$) compared to the 2010 class ($3.59$). 7. This analysis helps understand the performance differences between the two classes based on their test scores.