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Finding the Fourth Proportional to 426.44, 639.60 and 137.81

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Solution

The fourth proportional to 426.44, 639.60 and 137.81 is: 206.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.44 : 639.60 = 137.81 : x
  2. Step 2: Convert to fraction form
    426.44/639.60 = 137.81/x
  3. Step 3: Cross multiply
    426.44x = 639.60 × 137.81
  4. Step 4: Simplify right side
    426.44x = 88,144.36
  5. Step 5: Solve for x
    x = 88,144.36/426.44
  6. Step 6: Final answer
    x = 206.70

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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.