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Finding the Fourth Proportional to 819.45, 1,131.20 and 487.98

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Solution

The fourth proportional to 819.45, 1,131.20 and 487.98 is: 673.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.45 : 1,131.20 = 487.98 : x
  2. Step 2: Convert to fraction form
    819.45/1,131.20 = 487.98/x
  3. Step 3: Cross multiply
    819.45x = 1,131.20 × 487.98
  4. Step 4: Simplify right side
    819.45x = 552,002.98
  5. Step 5: Solve for x
    x = 552,002.98/819.45
  6. Step 6: Final answer
    x = 673.63

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.