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Finding the Fourth Proportional to 139.81, 192.84 and 87.38

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Solution

The fourth proportional to 139.81, 192.84 and 87.38 is: 120.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.81 : 192.84 = 87.38 : x
  2. Step 2: Convert to fraction form
    139.81/192.84 = 87.38/x
  3. Step 3: Cross multiply
    139.81x = 192.84 × 87.38
  4. Step 4: Simplify right side
    139.81x = 16,850.36
  5. Step 5: Solve for x
    x = 16,850.36/139.81
  6. Step 6: Final answer
    x = 120.52

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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.