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Finding the Fourth Proportional to 220.88, 331.20 and 66.78

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Solution

The fourth proportional to 220.88, 331.20 and 66.78 is: 100.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.88 : 331.20 = 66.78 : x
  2. Step 2: Convert to fraction form
    220.88/331.20 = 66.78/x
  3. Step 3: Cross multiply
    220.88x = 331.20 × 66.78
  4. Step 4: Simplify right side
    220.88x = 22,117.54
  5. Step 5: Solve for x
    x = 22,117.54/220.88
  6. Step 6: Final answer
    x = 100.13

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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.