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Finding the Fourth Proportional to 69.69, 104.64 and 57.78

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Solution

The fourth proportional to 69.69, 104.64 and 57.78 is: 86.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.69 : 104.64 = 57.78 : x
  2. Step 2: Convert to fraction form
    69.69/104.64 = 57.78/x
  3. Step 3: Cross multiply
    69.69x = 104.64 × 57.78
  4. Step 4: Simplify right side
    69.69x = 6,046.10
  5. Step 5: Solve for x
    x = 6,046.10/69.69
  6. Step 6: Final answer
    x = 86.76

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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.