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Finding the Fourth Proportional to 853.87, 1,279.21 and 487.55

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Solution

The fourth proportional to 853.87, 1,279.21 and 487.55 is: 730.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.87 : 1,279.21 = 487.55 : x
  2. Step 2: Convert to fraction form
    853.87/1,279.21 = 487.55/x
  3. Step 3: Cross multiply
    853.87x = 1,279.21 × 487.55
  4. Step 4: Simplify right side
    853.87x = 623,672.44
  5. Step 5: Solve for x
    x = 623,672.44/853.87
  6. Step 6: Final answer
    x = 730.41

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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.