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Finding the Fourth Proportional to 641.20, 884.64 and 392.38

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Solution

The fourth proportional to 641.20, 884.64 and 392.38 is: 541.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.20 : 884.64 = 392.38 : x
  2. Step 2: Convert to fraction form
    641.20/884.64 = 392.38/x
  3. Step 3: Cross multiply
    641.20x = 884.64 × 392.38
  4. Step 4: Simplify right side
    641.20x = 347,115.04
  5. Step 5: Solve for x
    x = 347,115.04/641.20
  6. Step 6: Final answer
    x = 541.35

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.