Data Interpretation

SAT Math — Data Interpretation: Tables, Graphs, and Scatterplots ## What Data Interpretation Questions Look Like These questions give you a graph, table, or chart and ask you to: - Read a specific value from the data - Calculate a percentage or ratio - Identify a trend or pattern - Compare two quantities - Evaluate whether a conclusion is supported by the data The most common formats: bar charts, line graphs, two-way tables, and scatterplots. ## Two-Way Tables A two-way table shows frequencies for two categorical variables. Example: | | Prefers Coffee | Prefers Tea | Total | |---|---|---|---| | Male | 45 | 25 | 70 | | Female | 30 | 40 | 70 | | Total | 75 | 65 | 140 | Reading the table: - 45 males prefer coffee - 65 total people prefer tea - 75/140 ≈ 53.6% of all respondents prefer coffee Conditional probability from tables: "What fraction of females prefer coffee?" = 30/70 ≈ 42.9% (You're looking at females ONLY — use the female row total, not the grand total) ## Scatterplots A scatterplot shows the relationship between two numerical variables. Each point represents one data observation. What to look for: - Direction: Positive correlation (both rise together) or negative correlation (one rises as the other falls) - Strength: Points tightly clustered around a line = strong correlation; scattered widely = weak - Outliers: Points that don't fit the overall pattern Line of best fit (trend line): The SAT often shows a line drawn through the data and asks you to: - Estimate the value for a given x using the line - Identify the slope of the line - Recognize…