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Finding the Fourth Proportional to 101.70, 140.38 and 81.07

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Solution

The fourth proportional to 101.70, 140.38 and 81.07 is: 111.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.70 : 140.38 = 81.07 : x
  2. Step 2: Convert to fraction form
    101.70/140.38 = 81.07/x
  3. Step 3: Cross multiply
    101.70x = 140.38 × 81.07
  4. Step 4: Simplify right side
    101.70x = 11,380.05
  5. Step 5: Solve for x
    x = 11,380.05/101.70
  6. Step 6: Final answer
    x = 111.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.