Home / 648-688

Finding the Third Proportional to 648 and 688

Calculator

Solution

The third proportional to 648 and 688 is: 730.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    648 : 688 = 688 : x
  2. Step 2: Convert to fraction form
    648/688 = 688/x
  3. Step 3: Cross multiply
    648x = 688 × 688
  4. Step 4: Simplify right side
    648x = 473,344
  5. Step 5: Solve for x
    x = 473,344/648
  6. Step 6: Final answer
    x = 730.47

Related Problems

Find third proportional to 324 and 344
Half scale
Find third proportional to 1,296 and 1,376
Double scale
Find third proportional to 650 and 690
Similar ratio
Find third proportional to 972 and 1,032
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.06) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.