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Finding the Fourth Proportional to 425.59, 638.05 and 391.42

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Solution

The fourth proportional to 425.59, 638.05 and 391.42 is: 586.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.59 : 638.05 = 391.42 : x
  2. Step 2: Convert to fraction form
    425.59/638.05 = 391.42/x
  3. Step 3: Cross multiply
    425.59x = 638.05 × 391.42
  4. Step 4: Simplify right side
    425.59x = 249,745.35
  5. Step 5: Solve for x
    x = 249,745.35/425.59
  6. Step 6: Final answer
    x = 586.82

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.