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Finding the Fourth Proportional to 108.85, 150.18 and 81.31

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Solution

The fourth proportional to 108.85, 150.18 and 81.31 is: 112.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.85 : 150.18 = 81.31 : x
  2. Step 2: Convert to fraction form
    108.85/150.18 = 81.31/x
  3. Step 3: Cross multiply
    108.85x = 150.18 × 81.31
  4. Step 4: Simplify right side
    108.85x = 12,211.14
  5. Step 5: Solve for x
    x = 12,211.14/108.85
  6. Step 6: Final answer
    x = 112.18

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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.