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Finding the Fourth Proportional to 138.32, 190.92 and 112.72

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Solution

The fourth proportional to 138.32, 190.92 and 112.72 is: 155.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.32 : 190.92 = 112.72 : x
  2. Step 2: Convert to fraction form
    138.32/190.92 = 112.72/x
  3. Step 3: Cross multiply
    138.32x = 190.92 × 112.72
  4. Step 4: Simplify right side
    138.32x = 21,520.50
  5. Step 5: Solve for x
    x = 21,520.50/138.32
  6. Step 6: Final answer
    x = 155.58

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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.