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Finding the Fourth Proportional to 425.96, 638.95 and 280.64

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Solution

The fourth proportional to 425.96, 638.95 and 280.64 is: 420.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.96 : 638.95 = 280.64 : x
  2. Step 2: Convert to fraction form
    425.96/638.95 = 280.64/x
  3. Step 3: Cross multiply
    425.96x = 638.95 × 280.64
  4. Step 4: Simplify right side
    425.96x = 179,317.64
  5. Step 5: Solve for x
    x = 179,317.64/425.96
  6. Step 6: Final answer
    x = 420.97

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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.