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Finding the Fourth Proportional to 638.05, 954.72 and 405.85

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Solution

The fourth proportional to 638.05, 954.72 and 405.85 is: 607.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.05 : 954.72 = 405.85 : x
  2. Step 2: Convert to fraction form
    638.05/954.72 = 405.85/x
  3. Step 3: Cross multiply
    638.05x = 954.72 × 405.85
  4. Step 4: Simplify right side
    638.05x = 387,473.11
  5. Step 5: Solve for x
    x = 387,473.11/638.05
  6. Step 6: Final answer
    x = 607.28

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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.