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Finding the Fourth Proportional to 724.38, 999.65 and 392.81

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Solution

The fourth proportional to 724.38, 999.65 and 392.81 is: 542.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    724.38 : 999.65 = 392.81 : x
  2. Step 2: Convert to fraction form
    724.38/999.65 = 392.81/x
  3. Step 3: Cross multiply
    724.38x = 999.65 × 392.81
  4. Step 4: Simplify right side
    724.38x = 392,665.55
  5. Step 5: Solve for x
    x = 392,665.55/724.38
  6. Step 6: Final answer
    x = 542.07

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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.