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Finding the Fourth Proportional to 278.97, 385.20 and 209.10

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Solution

The fourth proportional to 278.97, 385.20 and 209.10 is: 288.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.97 : 385.20 = 209.10 : x
  2. Step 2: Convert to fraction form
    278.97/385.20 = 209.10/x
  3. Step 3: Cross multiply
    278.97x = 385.20 × 209.10
  4. Step 4: Simplify right side
    278.97x = 80,545.32
  5. Step 5: Solve for x
    x = 80,545.32/278.97
  6. Step 6: Final answer
    x = 288.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.