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Finding the Fourth Proportional to 105.65, 145.83 and 81.06

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Solution

The fourth proportional to 105.65, 145.83 and 81.06 is: 111.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.65 : 145.83 = 81.06 : x
  2. Step 2: Convert to fraction form
    105.65/145.83 = 81.06/x
  3. Step 3: Cross multiply
    105.65x = 145.83 × 81.06
  4. Step 4: Simplify right side
    105.65x = 11,820.98
  5. Step 5: Solve for x
    x = 11,820.98/105.65
  6. Step 6: Final answer
    x = 111.89

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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.