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Finding the Fourth Proportional to 108.19, 161.91 and 85.17

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Solution

The fourth proportional to 108.19, 161.91 and 85.17 is: 127.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.19 : 161.91 = 85.17 : x
  2. Step 2: Convert to fraction form
    108.19/161.91 = 85.17/x
  3. Step 3: Cross multiply
    108.19x = 161.91 × 85.17
  4. Step 4: Simplify right side
    108.19x = 13,789.87
  5. Step 5: Solve for x
    x = 13,789.87/108.19
  6. Step 6: Final answer
    x = 127.46

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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.