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Finding the Fourth Proportional to 439.73, 655.59 and 428.51

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Solution

The fourth proportional to 439.73, 655.59 and 428.51 is: 638.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.73 : 655.59 = 428.51 : x
  2. Step 2: Convert to fraction form
    439.73/655.59 = 428.51/x
  3. Step 3: Cross multiply
    439.73x = 655.59 × 428.51
  4. Step 4: Simplify right side
    439.73x = 280,926.87
  5. Step 5: Solve for x
    x = 280,926.87/439.73
  6. Step 6: Final answer
    x = 638.86

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.