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Finding the Fourth Proportional to 154.87, 212.56 and 139.15

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Solution

The fourth proportional to 154.87, 212.56 and 139.15 is: 190.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.87 : 212.56 = 139.15 : x
  2. Step 2: Convert to fraction form
    154.87/212.56 = 139.15/x
  3. Step 3: Cross multiply
    154.87x = 212.56 × 139.15
  4. Step 4: Simplify right side
    154.87x = 29,576.66
  5. Step 5: Solve for x
    x = 29,576.66/154.87
  6. Step 6: Final answer
    x = 190.98

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.