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Finding the Fourth Proportional to 139.31, 192.19 and 87.59

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Solution

The fourth proportional to 139.31, 192.19 and 87.59 is: 120.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.31 : 192.19 = 87.59 : x
  2. Step 2: Convert to fraction form
    139.31/192.19 = 87.59/x
  3. Step 3: Cross multiply
    139.31x = 192.19 × 87.59
  4. Step 4: Simplify right side
    139.31x = 16,833.92
  5. Step 5: Solve for x
    x = 16,833.92/139.31
  6. Step 6: Final answer
    x = 120.84

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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.