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Finding the Fourth Proportional to 63.78, 87.82 and 56

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Solution

The fourth proportional to 63.78, 87.82 and 56 is: 77.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.78 : 87.82 = 56 : x
  2. Step 2: Convert to fraction form
    63.78/87.82 = 56/x
  3. Step 3: Cross multiply
    63.78x = 87.82 × 56
  4. Step 4: Simplify right side
    63.78x = 4,917.92
  5. Step 5: Solve for x
    x = 4,917.92/63.78
  6. Step 6: Final answer
    x = 77.11

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.