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Finding the Fourth Proportional to 857.34, 1,286.06 and 309.87

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Solution

The fourth proportional to 857.34, 1,286.06 and 309.87 is: 464.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.34 : 1,286.06 = 309.87 : x
  2. Step 2: Convert to fraction form
    857.34/1,286.06 = 309.87/x
  3. Step 3: Cross multiply
    857.34x = 1,286.06 × 309.87
  4. Step 4: Simplify right side
    857.34x = 398,509.86
  5. Step 5: Solve for x
    x = 398,509.86/857.34
  6. Step 6: Final answer
    x = 464.82

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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.