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Finding the Fourth Proportional to 426.94, 640.28 and 138.31

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Solution

The fourth proportional to 426.94, 640.28 and 138.31 is: 207.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.94 : 640.28 = 138.31 : x
  2. Step 2: Convert to fraction form
    426.94/640.28 = 138.31/x
  3. Step 3: Cross multiply
    426.94x = 640.28 × 138.31
  4. Step 4: Simplify right side
    426.94x = 88,557.13
  5. Step 5: Solve for x
    x = 88,557.13/426.94
  6. Step 6: Final answer
    x = 207.42

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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.