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Finding the Fourth Proportional to 71.72, 107.78 and 47.82

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Solution

The fourth proportional to 71.72, 107.78 and 47.82 is: 71.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.72 : 107.78 = 47.82 : x
  2. Step 2: Convert to fraction form
    71.72/107.78 = 47.82/x
  3. Step 3: Cross multiply
    71.72x = 107.78 × 47.82
  4. Step 4: Simplify right side
    71.72x = 5,153.80
  5. Step 5: Solve for x
    x = 5,153.80/71.72
  6. Step 6: Final answer
    x = 71.87

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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.