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Finding the Fourth Proportional to 219.78, 329.70 and 82.80

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Solution

The fourth proportional to 219.78, 329.70 and 82.80 is: 124.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.78 : 329.70 = 82.80 : x
  2. Step 2: Convert to fraction form
    219.78/329.70 = 82.80/x
  3. Step 3: Cross multiply
    219.78x = 329.70 × 82.80
  4. Step 4: Simplify right side
    219.78x = 27,299.16
  5. Step 5: Solve for x
    x = 27,299.16/219.78
  6. Step 6: Final answer
    x = 124.21

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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.