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Finding the Fourth Proportional to 138.53, 207.79 and 84.41

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Solution

The fourth proportional to 138.53, 207.79 and 84.41 is: 126.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.53 : 207.79 = 84.41 : x
  2. Step 2: Convert to fraction form
    138.53/207.79 = 84.41/x
  3. Step 3: Cross multiply
    138.53x = 207.79 × 84.41
  4. Step 4: Simplify right side
    138.53x = 17,539.55
  5. Step 5: Solve for x
    x = 17,539.55/138.53
  6. Step 6: Final answer
    x = 126.61

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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.