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Finding the Fourth Proportional to 428.52, 590.28 and 405

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Solution

The fourth proportional to 428.52, 590.28 and 405 is: 557.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.52 : 590.28 = 405 : x
  2. Step 2: Convert to fraction form
    428.52/590.28 = 405/x
  3. Step 3: Cross multiply
    428.52x = 590.28 × 405
  4. Step 4: Simplify right side
    428.52x = 239,063.40
  5. Step 5: Solve for x
    x = 239,063.40/428.52
  6. Step 6: Final answer
    x = 557.88

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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.