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Finding the Fourth Proportional to 857.62, 1,286.43 and 280.49

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Solution

The fourth proportional to 857.62, 1,286.43 and 280.49 is: 420.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.62 : 1,286.43 = 280.49 : x
  2. Step 2: Convert to fraction form
    857.62/1,286.43 = 280.49/x
  3. Step 3: Cross multiply
    857.62x = 1,286.43 × 280.49
  4. Step 4: Simplify right side
    857.62x = 360,829.35
  5. Step 5: Solve for x
    x = 360,829.35/857.62
  6. Step 6: Final answer
    x = 420.74

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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.