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Finding the Fourth Proportional to 8.78, 13.14 and 7.76

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Solution

The fourth proportional to 8.78, 13.14 and 7.76 is: 11.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.78 : 13.14 = 7.76 : x
  2. Step 2: Convert to fraction form
    8.78/13.14 = 7.76/x
  3. Step 3: Cross multiply
    8.78x = 13.14 × 7.76
  4. Step 4: Simplify right side
    8.78x = 101.90
  5. Step 5: Solve for x
    x = 101.90/8.78
  6. Step 6: Final answer
    x = 11.61

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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.