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Finding the Fourth Proportional to 428.65, 591.05 and 405.56

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Solution

The fourth proportional to 428.65, 591.05 and 405.56 is: 559.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.65 : 591.05 = 405.56 : x
  2. Step 2: Convert to fraction form
    428.65/591.05 = 405.56/x
  3. Step 3: Cross multiply
    428.65x = 591.05 × 405.56
  4. Step 4: Simplify right side
    428.65x = 239,708.73
  5. Step 5: Solve for x
    x = 239,708.73/428.65
  6. Step 6: Final answer
    x = 559.22

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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.