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Finding the Fourth Proportional to 80.67, 120.34 and 78.85

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Solution

The fourth proportional to 80.67, 120.34 and 78.85 is: 117.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.67 : 120.34 = 78.85 : x
  2. Step 2: Convert to fraction form
    80.67/120.34 = 78.85/x
  3. Step 3: Cross multiply
    80.67x = 120.34 × 78.85
  4. Step 4: Simplify right side
    80.67x = 9,488.81
  5. Step 5: Solve for x
    x = 9,488.81/80.67
  6. Step 6: Final answer
    x = 117.63

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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.