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Finding the Fourth Proportional to 138.42, 207.60 and 69.98

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Solution

The fourth proportional to 138.42, 207.60 and 69.98 is: 104.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.42 : 207.60 = 69.98 : x
  2. Step 2: Convert to fraction form
    138.42/207.60 = 69.98/x
  3. Step 3: Cross multiply
    138.42x = 207.60 × 69.98
  4. Step 4: Simplify right side
    138.42x = 14,527.85
  5. Step 5: Solve for x
    x = 14,527.85/138.42
  6. Step 6: Final answer
    x = 104.95

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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.