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Finding the Fourth Proportional to 644.18, 966.20 and 278.90

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Solution

The fourth proportional to 644.18, 966.20 and 278.90 is: 418.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.18 : 966.20 = 278.90 : x
  2. Step 2: Convert to fraction form
    644.18/966.20 = 278.90/x
  3. Step 3: Cross multiply
    644.18x = 966.20 × 278.90
  4. Step 4: Simplify right side
    644.18x = 269,473.18
  5. Step 5: Solve for x
    x = 269,473.18/644.18
  6. Step 6: Final answer
    x = 418.32

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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.