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Finding the Fourth Proportional to 108.31, 163.09 and 90.19

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Solution

The fourth proportional to 108.31, 163.09 and 90.19 is: 135.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.31 : 163.09 = 90.19 : x
  2. Step 2: Convert to fraction form
    108.31/163.09 = 90.19/x
  3. Step 3: Cross multiply
    108.31x = 163.09 × 90.19
  4. Step 4: Simplify right side
    108.31x = 14,709.09
  5. Step 5: Solve for x
    x = 14,709.09/108.31
  6. Step 6: Final answer
    x = 135.81

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.