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Finding the Fourth Proportional to 78.78, 118.17 and 68.76

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Solution

The fourth proportional to 78.78, 118.17 and 68.76 is: 103.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.78 : 118.17 = 68.76 : x
  2. Step 2: Convert to fraction form
    78.78/118.17 = 68.76/x
  3. Step 3: Cross multiply
    78.78x = 118.17 × 68.76
  4. Step 4: Simplify right side
    78.78x = 8,125.37
  5. Step 5: Solve for x
    x = 8,125.37/78.78
  6. Step 6: Final answer
    x = 103.14

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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.