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Finding the Fourth Proportional to 80.31, 110.70 and 61.86

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Solution

The fourth proportional to 80.31, 110.70 and 61.86 is: 85.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.31 : 110.70 = 61.86 : x
  2. Step 2: Convert to fraction form
    80.31/110.70 = 61.86/x
  3. Step 3: Cross multiply
    80.31x = 110.70 × 61.86
  4. Step 4: Simplify right side
    80.31x = 6,847.90
  5. Step 5: Solve for x
    x = 6,847.90/80.31
  6. Step 6: Final answer
    x = 85.27

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.