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Finding the Fourth Proportional to 154.92, 213.84 and 138.72

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Solution

The fourth proportional to 154.92, 213.84 and 138.72 is: 191.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.92 : 213.84 = 138.72 : x
  2. Step 2: Convert to fraction form
    154.92/213.84 = 138.72/x
  3. Step 3: Cross multiply
    154.92x = 213.84 × 138.72
  4. Step 4: Simplify right side
    154.92x = 29,663.88
  5. Step 5: Solve for x
    x = 29,663.88/154.92
  6. Step 6: Final answer
    x = 191.48

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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.