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Finding the Fourth Proportional to 139.89, 192.99 and 80.85

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Solution

The fourth proportional to 139.89, 192.99 and 80.85 is: 111.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.89 : 192.99 = 80.85 : x
  2. Step 2: Convert to fraction form
    139.89/192.99 = 80.85/x
  3. Step 3: Cross multiply
    139.89x = 192.99 × 80.85
  4. Step 4: Simplify right side
    139.89x = 15,603.24
  5. Step 5: Solve for x
    x = 15,603.24/139.89
  6. Step 6: Final answer
    x = 111.54

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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.