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Finding the Fourth Proportional to 80.11, 120.12 and 78.31

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Solution

The fourth proportional to 80.11, 120.12 and 78.31 is: 117.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.11 : 120.12 = 78.31 : x
  2. Step 2: Convert to fraction form
    80.11/120.12 = 78.31/x
  3. Step 3: Cross multiply
    80.11x = 120.12 × 78.31
  4. Step 4: Simplify right side
    80.11x = 9,406.60
  5. Step 5: Solve for x
    x = 9,406.60/80.11
  6. Step 6: Final answer
    x = 117.42

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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.