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Finding the Fourth Proportional to 81.11, 120.93 and 68.34

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Solution

The fourth proportional to 81.11, 120.93 and 68.34 is: 101.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.11 : 120.93 = 68.34 : x
  2. Step 2: Convert to fraction form
    81.11/120.93 = 68.34/x
  3. Step 3: Cross multiply
    81.11x = 120.93 × 68.34
  4. Step 4: Simplify right side
    81.11x = 8,264.36
  5. Step 5: Solve for x
    x = 8,264.36/81.11
  6. Step 6: Final answer
    x = 101.90

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.