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Finding the Fourth Proportional to 819.17, 1,229.99 and 409.71

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Solution

The fourth proportional to 819.17, 1,229.99 and 409.71 is: 615.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.17 : 1,229.99 = 409.71 : x
  2. Step 2: Convert to fraction form
    819.17/1,229.99 = 409.71/x
  3. Step 3: Cross multiply
    819.17x = 1,229.99 × 409.71
  4. Step 4: Simplify right side
    819.17x = 503,939.20
  5. Step 5: Solve for x
    x = 503,939.20/819.17
  6. Step 6: Final answer
    x = 615.18

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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.