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Finding the Fourth Proportional to 687.98, 949.31 and 408.22

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Solution

The fourth proportional to 687.98, 949.31 and 408.22 is: 563.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.98 : 949.31 = 408.22 : x
  2. Step 2: Convert to fraction form
    687.98/949.31 = 408.22/x
  3. Step 3: Cross multiply
    687.98x = 949.31 × 408.22
  4. Step 4: Simplify right side
    687.98x = 387,529.54
  5. Step 5: Solve for x
    x = 387,529.54/687.98
  6. Step 6: Final answer
    x = 563.29

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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.