SAT Tables, Percentages & Data Interpretation
SAT Tables, Percentages & Data Interpretation
Read the data first. Calculate second.
Learn to move confidently between tables, percentages, rates, comparisons, and multi-step SAT data questions.
What a Data Table Actually Shows
A table organizes information into rows and columns. Before calculating, identify exactly what each number represents.
| Month | Visitors | Purchases | Purchase Rate |
|---|---|---|---|
| May | 800 | 120 | 15% |
| June | 1,000 | 180 | 18% |
| July | 1,200 | 240 | 20% |
The last column is a rate: purchases divided by visitors.
Percent = Part ÷ Whole
Use
The difficult part is often choosing the correct whole. Complete the sentence mentally: “___ is what percent of ___?”
Reading Percentages from Tables
| Club A | Club B | Total | |
|---|---|---|---|
| Grade 9 | 18 | 12 | 30 |
| Grade 10 | 24 | 16 | 40 |
| Total | 42 | 28 | 70 |
The percentage of Grade 10 students in Club A is \(24/40=60\%\). The denominator is 40, not 70.
Percent Increase and Decrease
For an increase of \(r\%\), multiply by \(1+r/100\). For a decrease, multiply by \(1-r/100\).
Example: from 240 to 300, the increase is 60, so \(60/240=25\%\).
Percent Change vs. Percentage-Point Change
| Year | Option A |
|---|---|
| 2024 | 40% |
| 2025 | 50% |
The increase is 10 percentage points, but the percent increase is \((50-40)/40=25\%\).
Comparing Groups Fairly
| School | Students | Passed | Rate |
|---|---|---|---|
| A | 500 | 425 | 85% |
| B | 200 | 180 | 90% |
A has more students who passed, but B has the higher pass rate.
Tables with Rates and Units
| Machine | Items | Hours | Items/hour |
|---|---|---|---|
| A | 360 | 6 | 60 |
| B | 420 | 7 | 60 |
| C | 500 | 8 | 62.5 |
Machines A and B have the same rate despite different totals.
Finding a Missing Value from a Percentage
If 18% of a group is 54 students, then
Reverse-percentage questions are often more about setup than arithmetic.
Combining Rows or Categories
| Transportation | Students |
|---|---|
| Bus | 84 |
| Train | 66 |
| Walk | 30 |
| Other | 20 |
Bus or train: \((84+66)/200=75\%\). Add the relevant parts before dividing.
Tables That Describe a Linear Relationship
| x | 2 | 4 | 6 | 8 |
|---|---|---|---|---|
| y | 11 | 17 | 23 | 29 |
Every increase of 2 in x produces an increase of 6 in y, so \(m=3\). Using \((2,11)\), \(11=3(2)+b\), giving \(b=5\). Thus \(y=3x+5\).
Multi-Step Data Interpretation
A reliable order
- Identify exactly what is being asked.
- Locate the relevant row and column.
- Choose the correct numerator and denominator.
- Calculate.
- Check whether the result is reasonable.
What the Table Does — and Does Not — Tell You
A table supports only conclusions justified by the displayed data.
Advanced Practice — SAT-Style Data Interpretation
Original SATMath800 questions. The table or visual carries information that students must extract.
What percent of the students are enrolled in either robotics or debate?
| Activity | Students |
|---|---|
| Robotics | 36 |
| Debate | 24 |
| Art | 30 |
| Music | 10 |
\((36+24)/(36+24+30+10)=60\%\).
What percent of Grade 11 students chose option B?
| A | B | Total | |
|---|---|---|---|
| 10 | 42 | 18 | 60 |
| 11 | 36 | 24 | 60 |
| 12 | 30 | 30 | 60 |
Use the Grade 11 total: \(24/60=40\%\).
What was the percent increase in visitors?
| Month | Visitors |
|---|---|
| March | 800 |
| April | 920 |
\((920-800)/800=15\%\).
By what percent did the completion rate increase?
| Year | On-time completion |
|---|---|
| 2024 | 40% |
| 2025 | 50% |
The increase is 10 percentage points, but relative to 40% it is \(10/40=25\%\).
Which program had the greater approval rate?
| Program | Applications | Approvals |
|---|---|---|
| A | 600 | 450 |
| B | 320 | 256 |
A: 75%. B: 80%.
If 72 students represent 18% of the school, how many students are in the school?
| Participation | Percent | Number |
|---|---|---|
| Participate | 18% | 72 |
\(72=0.18N\), so \(N=400\).
What percentage travel by bus or train?
| Method | Students |
|---|---|
| Bus | 84 |
| Train | 60 |
| Walk | 48 |
| Car | 48 |
\((84+60)/240=60\%\).
Which equation represents the relationship?
| x | 1 | 3 | 5 | 7 |
|---|---|---|---|---|
| y | 7 | 13 | 19 | 25 |
Find the slope m first by using two points from the table. Let us pick \((1,7)\) and \((3,13)\) \(m=(13-7)/(3-1) = 6/2=3\). So the equation is \(y=3x+b\) . Using \((1,7)\), \(7=3+b\), so \(b=4\).
Which trip had the greatest average distance per liter?
| Trip | Distance (km) | Fuel (L) |
|---|---|---|
| A | 360 | 24 |
| B | 420 | 30 |
| C | 500 | 40 |
A = 360km/24L = 15 km/L, B = 14 km/L, C = 12.5 km/L.
How many Week 2 customers made a purchase?
| Week | Customers | Purchase rate |
|---|---|---|
| 1 | 800 | 15% |
| 2 | 1,200 | 18% |
\(0.18(1200)=216\).
Which statement is true?
| Assignment | Assigned | Completed |
|---|---|---|
| A | 400 | 320 |
| B | 250 | 200 |
A: 80%. B: 80%. A has more completions, but equal rates.
Fiber access represents 12% of households. If 2,400 households have fiber access, how many households are in the town?
| Access | Percent |
|---|---|
| Fiber | 12% |
| Cable | 48% |
| Other | 40% |
Enter your answer.
\(2400=0.12N\), so \(N=20,000\).
