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Finding the Fourth Proportional to 138.85, 191.76 and 112.90

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Solution

The fourth proportional to 138.85, 191.76 and 112.90 is: 155.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.85 : 191.76 = 112.90 : x
  2. Step 2: Convert to fraction form
    138.85/191.76 = 112.90/x
  3. Step 3: Cross multiply
    138.85x = 191.76 × 112.90
  4. Step 4: Simplify right side
    138.85x = 21,649.70
  5. Step 5: Solve for x
    x = 21,649.70/138.85
  6. Step 6: Final answer
    x = 155.92

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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.