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Finding the Fourth Proportional to 819.31, 1,130.28 and 487.55

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Solution

The fourth proportional to 819.31, 1,130.28 and 487.55 is: 672.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.31 : 1,130.28 = 487.55 : x
  2. Step 2: Convert to fraction form
    819.31/1,130.28 = 487.55/x
  3. Step 3: Cross multiply
    819.31x = 1,130.28 × 487.55
  4. Step 4: Simplify right side
    819.31x = 551,068.01
  5. Step 5: Solve for x
    x = 551,068.01/819.31
  6. Step 6: Final answer
    x = 672.60

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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.