Home / 478-689

Finding the Third Proportional to 478 and 689

Calculator

Solution

The third proportional to 478 and 689 is: 993.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    478 : 689 = 689 : x
  2. Step 2: Convert to fraction form
    478/689 = 689/x
  3. Step 3: Cross multiply
    478x = 689 × 689
  4. Step 4: Simplify right side
    478x = 474,721
  5. Step 5: Solve for x
    x = 474,721/478
  6. Step 6: Final answer
    x = 993.14

Related Problems

Find third proportional to 239 and 344.50
Half scale
Find third proportional to 956 and 1,378
Double scale
Find third proportional to 480 and 692
Similar ratio
Find third proportional to 717 and 1,033.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.44) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.