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Finding the Fourth Proportional to 425.32, 638.04 and 136.78

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Solution

The fourth proportional to 425.32, 638.04 and 136.78 is: 205.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.32 : 638.04 = 136.78 : x
  2. Step 2: Convert to fraction form
    425.32/638.04 = 136.78/x
  3. Step 3: Cross multiply
    425.32x = 638.04 × 136.78
  4. Step 4: Simplify right side
    425.32x = 87,271.11
  5. Step 5: Solve for x
    x = 87,271.11/425.32
  6. Step 6: Final answer
    x = 205.19

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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.