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Finding the Fourth Proportional to 138.87, 191.58 and 111.28

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Solution

The fourth proportional to 138.87, 191.58 and 111.28 is: 153.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.87 : 191.58 = 111.28 : x
  2. Step 2: Convert to fraction form
    138.87/191.58 = 111.28/x
  3. Step 3: Cross multiply
    138.87x = 191.58 × 111.28
  4. Step 4: Simplify right side
    138.87x = 21,319.02
  5. Step 5: Solve for x
    x = 21,319.02/138.87
  6. Step 6: Final answer
    x = 153.52

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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.