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Finding the Fourth Proportional to 105.22, 145.25 and 81.90

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Solution

The fourth proportional to 105.22, 145.25 and 81.90 is: 113.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.22 : 145.25 = 81.90 : x
  2. Step 2: Convert to fraction form
    105.22/145.25 = 81.90/x
  3. Step 3: Cross multiply
    105.22x = 145.25 × 81.90
  4. Step 4: Simplify right side
    105.22x = 11,895.98
  5. Step 5: Solve for x
    x = 11,895.98/105.22
  6. Step 6: Final answer
    x = 113.06

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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.