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Finding the Fourth Proportional to 428.83, 643.25 and 136.32

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Solution

The fourth proportional to 428.83, 643.25 and 136.32 is: 204.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.83 : 643.25 = 136.32 : x
  2. Step 2: Convert to fraction form
    428.83/643.25 = 136.32/x
  3. Step 3: Cross multiply
    428.83x = 643.25 × 136.32
  4. Step 4: Simplify right side
    428.83x = 87,687.84
  5. Step 5: Solve for x
    x = 87,687.84/428.83
  6. Step 6: Final answer
    x = 204.48

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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.