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Finding the Fourth Proportional to 278.49, 418.20 and 209.08

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Solution

The fourth proportional to 278.49, 418.20 and 209.08 is: 313.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.49 : 418.20 = 209.08 : x
  2. Step 2: Convert to fraction form
    278.49/418.20 = 209.08/x
  3. Step 3: Cross multiply
    278.49x = 418.20 × 209.08
  4. Step 4: Simplify right side
    278.49x = 87,437.88
  5. Step 5: Solve for x
    x = 87,437.88/278.49
  6. Step 6: Final answer
    x = 313.97

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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.