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Finding the Fourth Proportional to 103.17, 155.34 and 81.63

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Solution

The fourth proportional to 103.17, 155.34 and 81.63 is: 122.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.17 : 155.34 = 81.63 : x
  2. Step 2: Convert to fraction form
    103.17/155.34 = 81.63/x
  3. Step 3: Cross multiply
    103.17x = 155.34 × 81.63
  4. Step 4: Simplify right side
    103.17x = 12,680.40
  5. Step 5: Solve for x
    x = 12,680.40/103.17
  6. Step 6: Final answer
    x = 122.91

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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.