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Finding the Fourth Proportional to 278.20, 417.30 and 219.70

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Solution

The fourth proportional to 278.20, 417.30 and 219.70 is: 329.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.20 : 417.30 = 219.70 : x
  2. Step 2: Convert to fraction form
    278.20/417.30 = 219.70/x
  3. Step 3: Cross multiply
    278.20x = 417.30 × 219.70
  4. Step 4: Simplify right side
    278.20x = 91,680.81
  5. Step 5: Solve for x
    x = 91,680.81/278.20
  6. Step 6: Final answer
    x = 329.55

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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.