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Finding the Fourth Proportional to 111.78, 154.09 and 98.73

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Solution

The fourth proportional to 111.78, 154.09 and 98.73 is: 136.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    111.78 : 154.09 = 98.73 : x
  2. Step 2: Convert to fraction form
    111.78/154.09 = 98.73/x
  3. Step 3: Cross multiply
    111.78x = 154.09 × 98.73
  4. Step 4: Simplify right side
    111.78x = 15,213.31
  5. Step 5: Solve for x
    x = 15,213.31/111.78
  6. Step 6: Final answer
    x = 136.10

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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.