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Finding the Fourth Proportional to 138.98, 208.56 and 102.99

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Solution

The fourth proportional to 138.98, 208.56 and 102.99 is: 154.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.98 : 208.56 = 102.99 : x
  2. Step 2: Convert to fraction form
    138.98/208.56 = 102.99/x
  3. Step 3: Cross multiply
    138.98x = 208.56 × 102.99
  4. Step 4: Simplify right side
    138.98x = 21,479.59
  5. Step 5: Solve for x
    x = 21,479.59/138.98
  6. Step 6: Final answer
    x = 154.56

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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.