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Finding the Fourth Proportional to 77.98, 116.40 and 68.86

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Solution

The fourth proportional to 77.98, 116.40 and 68.86 is: 102.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.98 : 116.40 = 68.86 : x
  2. Step 2: Convert to fraction form
    77.98/116.40 = 68.86/x
  3. Step 3: Cross multiply
    77.98x = 116.40 × 68.86
  4. Step 4: Simplify right side
    77.98x = 8,015.30
  5. Step 5: Solve for x
    x = 8,015.30/77.98
  6. Step 6: Final answer
    x = 102.79

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.