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Finding the Fourth Proportional to 103.28, 142.47 and 81.41

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Solution

The fourth proportional to 103.28, 142.47 and 81.41 is: 112.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.28 : 142.47 = 81.41 : x
  2. Step 2: Convert to fraction form
    103.28/142.47 = 81.41/x
  3. Step 3: Cross multiply
    103.28x = 142.47 × 81.41
  4. Step 4: Simplify right side
    103.28x = 11,597.77
  5. Step 5: Solve for x
    x = 11,597.77/103.28
  6. Step 6: Final answer
    x = 112.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.