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Finding the Fourth Proportional to 138.07, 190.38 and 129.70

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Solution

The fourth proportional to 138.07, 190.38 and 129.70 is: 178.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.07 : 190.38 = 129.70 : x
  2. Step 2: Convert to fraction form
    138.07/190.38 = 129.70/x
  3. Step 3: Cross multiply
    138.07x = 190.38 × 129.70
  4. Step 4: Simplify right side
    138.07x = 24,692.29
  5. Step 5: Solve for x
    x = 24,692.29/138.07
  6. Step 6: Final answer
    x = 178.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.