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Finding the Fourth Proportional to 869.10, 1,199.43 and 519.78

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Solution

The fourth proportional to 869.10, 1,199.43 and 519.78 is: 717.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.10 : 1,199.43 = 519.78 : x
  2. Step 2: Convert to fraction form
    869.10/1,199.43 = 519.78/x
  3. Step 3: Cross multiply
    869.10x = 1,199.43 × 519.78
  4. Step 4: Simplify right side
    869.10x = 623,439.73
  5. Step 5: Solve for x
    x = 623,439.73/869.10
  6. Step 6: Final answer
    x = 717.34

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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.