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Finding the Fourth Proportional to 103.74, 143.08 and 81.87

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Solution

The fourth proportional to 103.74, 143.08 and 81.87 is: 112.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.74 : 143.08 = 81.87 : x
  2. Step 2: Convert to fraction form
    103.74/143.08 = 81.87/x
  3. Step 3: Cross multiply
    103.74x = 143.08 × 81.87
  4. Step 4: Simplify right side
    103.74x = 11,713.96
  5. Step 5: Solve for x
    x = 11,713.96/103.74
  6. Step 6: Final answer
    x = 112.92

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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.