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Finding the Fourth Proportional to 103.80, 143.08 and 81.52

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Solution

The fourth proportional to 103.80, 143.08 and 81.52 is: 112.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.80 : 143.08 = 81.52 : x
  2. Step 2: Convert to fraction form
    103.80/143.08 = 81.52/x
  3. Step 3: Cross multiply
    103.80x = 143.08 × 81.52
  4. Step 4: Simplify right side
    103.80x = 11,663.88
  5. Step 5: Solve for x
    x = 11,663.88/103.80
  6. Step 6: Final answer
    x = 112.37

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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.