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Finding the Fourth Proportional to 80.73, 120.99 and 51.78

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Solution

The fourth proportional to 80.73, 120.99 and 51.78 is: 77.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.73 : 120.99 = 51.78 : x
  2. Step 2: Convert to fraction form
    80.73/120.99 = 51.78/x
  3. Step 3: Cross multiply
    80.73x = 120.99 × 51.78
  4. Step 4: Simplify right side
    80.73x = 6,264.86
  5. Step 5: Solve for x
    x = 6,264.86/80.73
  6. Step 6: Final answer
    x = 77.60

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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.