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Finding the Fourth Proportional to 857.94, 1,286.91 and 280.82

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Solution

The fourth proportional to 857.94, 1,286.91 and 280.82 is: 421.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.94 : 1,286.91 = 280.82 : x
  2. Step 2: Convert to fraction form
    857.94/1,286.91 = 280.82/x
  3. Step 3: Cross multiply
    857.94x = 1,286.91 × 280.82
  4. Step 4: Simplify right side
    857.94x = 361,383.63
  5. Step 5: Solve for x
    x = 361,383.63/857.94
  6. Step 6: Final answer
    x = 421.22

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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.