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Finding the Fourth Proportional to 69.87, 104.54 and 51.78

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Solution

The fourth proportional to 69.87, 104.54 and 51.78 is: 77.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.87 : 104.54 = 51.78 : x
  2. Step 2: Convert to fraction form
    69.87/104.54 = 51.78/x
  3. Step 3: Cross multiply
    69.87x = 104.54 × 51.78
  4. Step 4: Simplify right side
    69.87x = 5,412.82
  5. Step 5: Solve for x
    x = 5,412.82/69.87
  6. Step 6: Final answer
    x = 77.47

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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.