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Finding the Fourth Proportional to 278.91, 418.45 and 221.16

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Solution

The fourth proportional to 278.91, 418.45 and 221.16 is: 331.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.91 : 418.45 = 221.16 : x
  2. Step 2: Convert to fraction form
    278.91/418.45 = 221.16/x
  3. Step 3: Cross multiply
    278.91x = 418.45 × 221.16
  4. Step 4: Simplify right side
    278.91x = 92,542.28
  5. Step 5: Solve for x
    x = 92,542.28/278.91
  6. Step 6: Final answer
    x = 331.80

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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.