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Finding the Fourth Proportional to 108.02, 161.72 and 86.39

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Solution

The fourth proportional to 108.02, 161.72 and 86.39 is: 129.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.02 : 161.72 = 86.39 : x
  2. Step 2: Convert to fraction form
    108.02/161.72 = 86.39/x
  3. Step 3: Cross multiply
    108.02x = 161.72 × 86.39
  4. Step 4: Simplify right side
    108.02x = 13,969.75
  5. Step 5: Solve for x
    x = 13,969.75/108.02
  6. Step 6: Final answer
    x = 129.33

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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.