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Finding the Fourth Proportional to 428.20, 590.34 and 405.96

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Solution

The fourth proportional to 428.20, 590.34 and 405.96 is: 559.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.20 : 590.34 = 405.96 : x
  2. Step 2: Convert to fraction form
    428.20/590.34 = 405.96/x
  3. Step 3: Cross multiply
    428.20x = 590.34 × 405.96
  4. Step 4: Simplify right side
    428.20x = 239,654.43
  5. Step 5: Solve for x
    x = 239,654.43/428.20
  6. Step 6: Final answer
    x = 559.68

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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.