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Finding the Fourth Proportional to 120.38, 180.41 and 81.77

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Solution

The fourth proportional to 120.38, 180.41 and 81.77 is: 122.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.38 : 180.41 = 81.77 : x
  2. Step 2: Convert to fraction form
    120.38/180.41 = 81.77/x
  3. Step 3: Cross multiply
    120.38x = 180.41 × 81.77
  4. Step 4: Simplify right side
    120.38x = 14,750.81
  5. Step 5: Solve for x
    x = 14,750.81/120.38
  6. Step 6: Final answer
    x = 122.54

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.