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Finding the Fourth Proportional to 76.87, 115.17 and 47.98

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Solution

The fourth proportional to 76.87, 115.17 and 47.98 is: 71.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.87 : 115.17 = 47.98 : x
  2. Step 2: Convert to fraction form
    76.87/115.17 = 47.98/x
  3. Step 3: Cross multiply
    76.87x = 115.17 × 47.98
  4. Step 4: Simplify right side
    76.87x = 5,525.86
  5. Step 5: Solve for x
    x = 5,525.86/76.87
  6. Step 6: Final answer
    x = 71.89

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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.