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Finding the Fourth Proportional to 409.20, 609.60 and 397.92

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Solution

The fourth proportional to 409.20, 609.60 and 397.92 is: 592.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.20 : 609.60 = 397.92 : x
  2. Step 2: Convert to fraction form
    409.20/609.60 = 397.92/x
  3. Step 3: Cross multiply
    409.20x = 609.60 × 397.92
  4. Step 4: Simplify right side
    409.20x = 242,572.03
  5. Step 5: Solve for x
    x = 242,572.03/409.20
  6. Step 6: Final answer
    x = 592.80

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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.