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Finding the Fourth Proportional to 629.57, 868.91 and 390.41

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Solution

The fourth proportional to 629.57, 868.91 and 390.41 is: 538.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.57 : 868.91 = 390.41 : x
  2. Step 2: Convert to fraction form
    629.57/868.91 = 390.41/x
  3. Step 3: Cross multiply
    629.57x = 868.91 × 390.41
  4. Step 4: Simplify right side
    629.57x = 339,231.15
  5. Step 5: Solve for x
    x = 339,231.15/629.57
  6. Step 6: Final answer
    x = 538.83

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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.