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Finding the Fourth Proportional to 138.04, 208 and 115.72

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Solution

The fourth proportional to 138.04, 208 and 115.72 is: 174.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.04 : 208 = 115.72 : x
  2. Step 2: Convert to fraction form
    138.04/208 = 115.72/x
  3. Step 3: Cross multiply
    138.04x = 208 × 115.72
  4. Step 4: Simplify right side
    138.04x = 24,069.76
  5. Step 5: Solve for x
    x = 24,069.76/138.04
  6. Step 6: Final answer
    x = 174.37

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.