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Finding the Fourth Proportional to 103.31, 154.89 and 86.30

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Solution

The fourth proportional to 103.31, 154.89 and 86.30 is: 129.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.31 : 154.89 = 86.30 : x
  2. Step 2: Convert to fraction form
    103.31/154.89 = 86.30/x
  3. Step 3: Cross multiply
    103.31x = 154.89 × 86.30
  4. Step 4: Simplify right side
    103.31x = 13,366.23
  5. Step 5: Solve for x
    x = 13,366.23/103.31
  6. Step 6: Final answer
    x = 129.39

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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.