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Finding the Fourth Proportional to 643.96, 966.22 and 278.66

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Solution

The fourth proportional to 643.96, 966.22 and 278.66 is: 418.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.96 : 966.22 = 278.66 : x
  2. Step 2: Convert to fraction form
    643.96/966.22 = 278.66/x
  3. Step 3: Cross multiply
    643.96x = 966.22 × 278.66
  4. Step 4: Simplify right side
    643.96x = 269,246.87
  5. Step 5: Solve for x
    x = 269,246.87/643.96
  6. Step 6: Final answer
    x = 418.11

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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.