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Finding the Fourth Proportional to 120.87, 180.97 and 100.66

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Solution

The fourth proportional to 120.87, 180.97 and 100.66 is: 150.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.87 : 180.97 = 100.66 : x
  2. Step 2: Convert to fraction form
    120.87/180.97 = 100.66/x
  3. Step 3: Cross multiply
    120.87x = 180.97 × 100.66
  4. Step 4: Simplify right side
    120.87x = 18,215.54
  5. Step 5: Solve for x
    x = 18,215.54/120.87
  6. Step 6: Final answer
    x = 150.70

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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.