Home / 628.03-688.78

Finding the Third Proportional to 628.03 and 688.78

Calculator

Solution

The third proportional to 628.03 and 688.78 is: 755.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.03 : 688.78 = 688.78 : x
  2. Step 2: Convert to fraction form
    628.03/688.78 = 688.78/x
  3. Step 3: Cross multiply
    628.03x = 688.78 × 688.78
  4. Step 4: Simplify right side
    628.03x = 474,419.61
  5. Step 5: Solve for x
    x = 474,419.61/628.03
  6. Step 6: Final answer
    x = 755.41

Related Problems

Find third proportional to 314.02 and 344.39
Half scale
Find third proportional to 1,256.06 and 1,377.56
Double scale
Find third proportional to 630 and 691
Similar ratio
Find third proportional to 942.05 and 1,033.17
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.10) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.