Home / 680-871

Finding the Third Proportional to 680 and 871

Calculator

Solution

The third proportional to 680 and 871 is: 1,115.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    680 : 871 = 871 : x
  2. Step 2: Convert to fraction form
    680/871 = 871/x
  3. Step 3: Cross multiply
    680x = 871 × 871
  4. Step 4: Simplify right side
    680x = 758,641
  5. Step 5: Solve for x
    x = 758,641/680
  6. Step 6: Final answer
    x = 1,115.65

Related Problems

Find third proportional to 340 and 435.50
Half scale
Find third proportional to 1,360 and 1,742
Double scale
Find third proportional to 682 and 874
Similar ratio
Find third proportional to 1,020 and 1,306.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.28) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.