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Finding the Fourth Proportional to 80.66, 120.22 and 78.44

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Solution

The fourth proportional to 80.66, 120.22 and 78.44 is: 116.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.66 : 120.22 = 78.44 : x
  2. Step 2: Convert to fraction form
    80.66/120.22 = 78.44/x
  3. Step 3: Cross multiply
    80.66x = 120.22 × 78.44
  4. Step 4: Simplify right side
    80.66x = 9,429.26
  5. Step 5: Solve for x
    x = 9,429.26/80.66
  6. Step 6: Final answer
    x = 116.90

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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.