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Finding the Fourth Proportional to 869.78, 1,200.13 and 520.34

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Solution

The fourth proportional to 869.78, 1,200.13 and 520.34 is: 717.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.78 : 1,200.13 = 520.34 : x
  2. Step 2: Convert to fraction form
    869.78/1,200.13 = 520.34/x
  3. Step 3: Cross multiply
    869.78x = 1,200.13 × 520.34
  4. Step 4: Simplify right side
    869.78x = 624,475.64
  5. Step 5: Solve for x
    x = 624,475.64/869.78
  6. Step 6: Final answer
    x = 717.97

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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.