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Finding the Fourth Proportional to 120.20, 180.34 and 72.12

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Solution

The fourth proportional to 120.20, 180.34 and 72.12 is: 108.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.20 : 180.34 = 72.12 : x
  2. Step 2: Convert to fraction form
    120.20/180.34 = 72.12/x
  3. Step 3: Cross multiply
    120.20x = 180.34 × 72.12
  4. Step 4: Simplify right side
    120.20x = 13,006.12
  5. Step 5: Solve for x
    x = 13,006.12/120.20
  6. Step 6: Final answer
    x = 108.20

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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.