Home / 609-678

Finding the Third Proportional to 609 and 678

Calculator

Solution

The third proportional to 609 and 678 is: 754.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    609 : 678 = 678 : x
  2. Step 2: Convert to fraction form
    609/678 = 678/x
  3. Step 3: Cross multiply
    609x = 678 × 678
  4. Step 4: Simplify right side
    609x = 459,684
  5. Step 5: Solve for x
    x = 459,684/609
  6. Step 6: Final answer
    x = 754.82

Related Problems

Find third proportional to 304.50 and 339
Half scale
Find third proportional to 1,218 and 1,356
Double scale
Find third proportional to 611 and 680
Similar ratio
Find third proportional to 913.50 and 1,017
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.11) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.