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Finding the Fourth Proportional to 406.20, 609.18 and 213.72

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Solution

The fourth proportional to 406.20, 609.18 and 213.72 is: 320.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.20 : 609.18 = 213.72 : x
  2. Step 2: Convert to fraction form
    406.20/609.18 = 213.72/x
  3. Step 3: Cross multiply
    406.20x = 609.18 × 213.72
  4. Step 4: Simplify right side
    406.20x = 130,193.95
  5. Step 5: Solve for x
    x = 130,193.95/406.20
  6. Step 6: Final answer
    x = 320.52

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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.