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Finding the Fourth Proportional to 108.82, 163.18 and 78.31

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Solution

The fourth proportional to 108.82, 163.18 and 78.31 is: 117.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.82 : 163.18 = 78.31 : x
  2. Step 2: Convert to fraction form
    108.82/163.18 = 78.31/x
  3. Step 3: Cross multiply
    108.82x = 163.18 × 78.31
  4. Step 4: Simplify right side
    108.82x = 12,778.63
  5. Step 5: Solve for x
    x = 12,778.63/108.82
  6. Step 6: Final answer
    x = 117.43

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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.