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Finding the Fourth Proportional to 219.60, 329.45 and 138.50

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Solution

The fourth proportional to 219.60, 329.45 and 138.50 is: 207.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.60 : 329.45 = 138.50 : x
  2. Step 2: Convert to fraction form
    219.60/329.45 = 138.50/x
  3. Step 3: Cross multiply
    219.60x = 329.45 × 138.50
  4. Step 4: Simplify right side
    219.60x = 45,628.83
  5. Step 5: Solve for x
    x = 45,628.83/219.60
  6. Step 6: Final answer
    x = 207.78

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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.