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Finding the Fourth Proportional to 100.95, 138.83 and 81.03

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Solution

The fourth proportional to 100.95, 138.83 and 81.03 is: 111.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.95 : 138.83 = 81.03 : x
  2. Step 2: Convert to fraction form
    100.95/138.83 = 81.03/x
  3. Step 3: Cross multiply
    100.95x = 138.83 × 81.03
  4. Step 4: Simplify right side
    100.95x = 11,248.99
  5. Step 5: Solve for x
    x = 11,248.99/100.95
  6. Step 6: Final answer
    x = 111.43

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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.