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Finding the Fourth Proportional to 420.92, 580.83 and 389.96

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Solution

The fourth proportional to 420.92, 580.83 and 389.96 is: 538.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.92 : 580.83 = 389.96 : x
  2. Step 2: Convert to fraction form
    420.92/580.83 = 389.96/x
  3. Step 3: Cross multiply
    420.92x = 580.83 × 389.96
  4. Step 4: Simplify right side
    420.92x = 226,500.47
  5. Step 5: Solve for x
    x = 226,500.47/420.92
  6. Step 6: Final answer
    x = 538.11

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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.