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Finding the Fourth Proportional to 120.72, 180.72 and 69.27

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Solution

The fourth proportional to 120.72, 180.72 and 69.27 is: 103.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.72 : 180.72 = 69.27 : x
  2. Step 2: Convert to fraction form
    120.72/180.72 = 69.27/x
  3. Step 3: Cross multiply
    120.72x = 180.72 × 69.27
  4. Step 4: Simplify right side
    120.72x = 12,518.47
  5. Step 5: Solve for x
    x = 12,518.47/120.72
  6. Step 6: Final answer
    x = 103.70

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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.