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Finding the Fourth Proportional to 154.78, 213.57 and 103

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Solution

The fourth proportional to 154.78, 213.57 and 103 is: 142.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.78 : 213.57 = 103 : x
  2. Step 2: Convert to fraction form
    154.78/213.57 = 103/x
  3. Step 3: Cross multiply
    154.78x = 213.57 × 103
  4. Step 4: Simplify right side
    154.78x = 21,997.71
  5. Step 5: Solve for x
    x = 21,997.71/154.78
  6. Step 6: Final answer
    x = 142.12

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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.