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Finding the Fourth Proportional to 140.87, 212.36 and 138.77

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Solution

The fourth proportional to 140.87, 212.36 and 138.77 is: 209.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.87 : 212.36 = 138.77 : x
  2. Step 2: Convert to fraction form
    140.87/212.36 = 138.77/x
  3. Step 3: Cross multiply
    140.87x = 212.36 × 138.77
  4. Step 4: Simplify right side
    140.87x = 29,469.20
  5. Step 5: Solve for x
    x = 29,469.20/140.87
  6. Step 6: Final answer
    x = 209.19

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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.