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Finding the Fourth Proportional to 428.18, 638.15 and 424.61

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Solution

The fourth proportional to 428.18, 638.15 and 424.61 is: 632.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.18 : 638.15 = 424.61 : x
  2. Step 2: Convert to fraction form
    428.18/638.15 = 424.61/x
  3. Step 3: Cross multiply
    428.18x = 638.15 × 424.61
  4. Step 4: Simplify right side
    428.18x = 270,961.68
  5. Step 5: Solve for x
    x = 270,961.68/428.18
  6. Step 6: Final answer
    x = 632.82

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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.