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Finding the Fourth Proportional to 101.42, 140.05 and 80.79

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Solution

The fourth proportional to 101.42, 140.05 and 80.79 is: 111.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.42 : 140.05 = 80.79 : x
  2. Step 2: Convert to fraction form
    101.42/140.05 = 80.79/x
  3. Step 3: Cross multiply
    101.42x = 140.05 × 80.79
  4. Step 4: Simplify right side
    101.42x = 11,314.18
  5. Step 5: Solve for x
    x = 11,314.18/101.42
  6. Step 6: Final answer
    x = 111.56

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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.