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Finding the Fourth Proportional to 857.43, 1,286.14 and 309.61

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Solution

The fourth proportional to 857.43, 1,286.14 and 309.61 is: 464.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.43 : 1,286.14 = 309.61 : x
  2. Step 2: Convert to fraction form
    857.43/1,286.14 = 309.61/x
  3. Step 3: Cross multiply
    857.43x = 1,286.14 × 309.61
  4. Step 4: Simplify right side
    857.43x = 398,201.85
  5. Step 5: Solve for x
    x = 398,201.85/857.43
  6. Step 6: Final answer
    x = 464.41

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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.