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Finding the Fourth Proportional to 57.94, 86.78 and 39.85

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Solution

The fourth proportional to 57.94, 86.78 and 39.85 is: 59.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.94 : 86.78 = 39.85 : x
  2. Step 2: Convert to fraction form
    57.94/86.78 = 39.85/x
  3. Step 3: Cross multiply
    57.94x = 86.78 × 39.85
  4. Step 4: Simplify right side
    57.94x = 3,458.07
  5. Step 5: Solve for x
    x = 3,458.07/57.94
  6. Step 6: Final answer
    x = 59.69

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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.