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Finding the Fourth Proportional to 426.63, 640.01 and 138.09

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Solution

The fourth proportional to 426.63, 640.01 and 138.09 is: 207.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.63 : 640.01 = 138.09 : x
  2. Step 2: Convert to fraction form
    426.63/640.01 = 138.09/x
  3. Step 3: Cross multiply
    426.63x = 640.01 × 138.09
  4. Step 4: Simplify right side
    426.63x = 88,375.09
  5. Step 5: Solve for x
    x = 88,375.09/426.63
  6. Step 6: Final answer
    x = 207.15

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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.