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Finding the Fourth Proportional to 108.31, 161.74 and 90.90

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Solution

The fourth proportional to 108.31, 161.74 and 90.90 is: 135.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.31 : 161.74 = 90.90 : x
  2. Step 2: Convert to fraction form
    108.31/161.74 = 90.90/x
  3. Step 3: Cross multiply
    108.31x = 161.74 × 90.90
  4. Step 4: Simplify right side
    108.31x = 14,702.17
  5. Step 5: Solve for x
    x = 14,702.17/108.31
  6. Step 6: Final answer
    x = 135.74

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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.