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Finding the Fourth Proportional to 426.39, 639.63 and 137.82

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Solution

The fourth proportional to 426.39, 639.63 and 137.82 is: 206.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.39 : 639.63 = 137.82 : x
  2. Step 2: Convert to fraction form
    426.39/639.63 = 137.82/x
  3. Step 3: Cross multiply
    426.39x = 639.63 × 137.82
  4. Step 4: Simplify right side
    426.39x = 88,153.81
  5. Step 5: Solve for x
    x = 88,153.81/426.39
  6. Step 6: Final answer
    x = 206.74

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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.