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Finding the Fourth Proportional to 120.45, 180.39 and 69.15

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Solution

The fourth proportional to 120.45, 180.39 and 69.15 is: 103.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.45 : 180.39 = 69.15 : x
  2. Step 2: Convert to fraction form
    120.45/180.39 = 69.15/x
  3. Step 3: Cross multiply
    120.45x = 180.39 × 69.15
  4. Step 4: Simplify right side
    120.45x = 12,473.97
  5. Step 5: Solve for x
    x = 12,473.97/120.45
  6. Step 6: Final answer
    x = 103.56

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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.