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Finding the Fourth Proportional to 120.80, 180.92 and 112.70

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Solution

The fourth proportional to 120.80, 180.92 and 112.70 is: 168.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.80 : 180.92 = 112.70 : x
  2. Step 2: Convert to fraction form
    120.80/180.92 = 112.70/x
  3. Step 3: Cross multiply
    120.80x = 180.92 × 112.70
  4. Step 4: Simplify right side
    120.80x = 20,389.68
  5. Step 5: Solve for x
    x = 20,389.68/120.80
  6. Step 6: Final answer
    x = 168.79

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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.