Home / 261-489

Finding the Third Proportional to 261 and 489

Calculator

Solution

The third proportional to 261 and 489 is: 916.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    261 : 489 = 489 : x
  2. Step 2: Convert to fraction form
    261/489 = 489/x
  3. Step 3: Cross multiply
    261x = 489 × 489
  4. Step 4: Simplify right side
    261x = 239,121
  5. Step 5: Solve for x
    x = 239,121/261
  6. Step 6: Final answer
    x = 916.17

Related Problems

Find third proportional to 130.50 and 244.50
Half scale
Find third proportional to 522 and 978
Double scale
Find third proportional to 263 and 493
Similar ratio
Find third proportional to 391.50 and 733.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.87) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.