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Finding the Fourth Proportional to 57.87, 86.72 and 39.80

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Solution

The fourth proportional to 57.87, 86.72 and 39.80 is: 59.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.87 : 86.72 = 39.80 : x
  2. Step 2: Convert to fraction form
    57.87/86.72 = 39.80/x
  3. Step 3: Cross multiply
    57.87x = 86.72 × 39.80
  4. Step 4: Simplify right side
    57.87x = 3,450.82
  5. Step 5: Solve for x
    x = 3,450.82/57.87
  6. Step 6: Final answer
    x = 59.63

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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.