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Finding the Fourth Proportional to 138.78, 192.86 and 137.06

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Solution

The fourth proportional to 138.78, 192.86 and 137.06 is: 190.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.78 : 192.86 = 137.06 : x
  2. Step 2: Convert to fraction form
    138.78/192.86 = 137.06/x
  3. Step 3: Cross multiply
    138.78x = 192.86 × 137.06
  4. Step 4: Simplify right side
    138.78x = 26,431.74
  5. Step 5: Solve for x
    x = 26,431.74/138.78
  6. Step 6: Final answer
    x = 190.46

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.