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Finding the Fourth Proportional to 78.27, 107.39 and 76.47

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Solution

The fourth proportional to 78.27, 107.39 and 76.47 is: 104.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.27 : 107.39 = 76.47 : x
  2. Step 2: Convert to fraction form
    78.27/107.39 = 76.47/x
  3. Step 3: Cross multiply
    78.27x = 107.39 × 76.47
  4. Step 4: Simplify right side
    78.27x = 8,211.73
  5. Step 5: Solve for x
    x = 8,211.73/78.27
  6. Step 6: Final answer
    x = 104.92

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.