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Finding the Fourth Proportional to 426.90, 640.31 and 118.73

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Solution

The fourth proportional to 426.90, 640.31 and 118.73 is: 178.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.90 : 640.31 = 118.73 : x
  2. Step 2: Convert to fraction form
    426.90/640.31 = 118.73/x
  3. Step 3: Cross multiply
    426.90x = 640.31 × 118.73
  4. Step 4: Simplify right side
    426.90x = 76,025.90
  5. Step 5: Solve for x
    x = 76,025.90/426.90
  6. Step 6: Final answer
    x = 178.09

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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.