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Finding the Fourth Proportional to 220.69, 331.05 and 66.61

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Solution

The fourth proportional to 220.69, 331.05 and 66.61 is: 99.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.69 : 331.05 = 66.61 : x
  2. Step 2: Convert to fraction form
    220.69/331.05 = 66.61/x
  3. Step 3: Cross multiply
    220.69x = 331.05 × 66.61
  4. Step 4: Simplify right side
    220.69x = 22,049.25
  5. Step 5: Solve for x
    x = 22,049.25/220.69
  6. Step 6: Final answer
    x = 99.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.