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Finding the Fourth Proportional to 819.15, 1,130.15 and 487.39

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Solution

The fourth proportional to 819.15, 1,130.15 and 487.39 is: 672.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.15 : 1,130.15 = 487.39 : x
  2. Step 2: Convert to fraction form
    819.15/1,130.15 = 487.39/x
  3. Step 3: Cross multiply
    819.15x = 1,130.15 × 487.39
  4. Step 4: Simplify right side
    819.15x = 550,822.20
  5. Step 5: Solve for x
    x = 550,822.20/819.15
  6. Step 6: Final answer
    x = 672.43

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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.