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Finding the Fourth Proportional to 251.97, 377.90 and 78.61

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Solution

The fourth proportional to 251.97, 377.90 and 78.61 is: 117.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    251.97 : 377.90 = 78.61 : x
  2. Step 2: Convert to fraction form
    251.97/377.90 = 78.61/x
  3. Step 3: Cross multiply
    251.97x = 377.90 × 78.61
  4. Step 4: Simplify right side
    251.97x = 29,706.72
  5. Step 5: Solve for x
    x = 29,706.72/251.97
  6. Step 6: Final answer
    x = 117.90

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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.