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Finding the Fourth Proportional to 666.47, 999.81 and 394.31

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Solution

The fourth proportional to 666.47, 999.81 and 394.31 is: 591.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.47 : 999.81 = 394.31 : x
  2. Step 2: Convert to fraction form
    666.47/999.81 = 394.31/x
  3. Step 3: Cross multiply
    666.47x = 999.81 × 394.31
  4. Step 4: Simplify right side
    666.47x = 394,237.58
  5. Step 5: Solve for x
    x = 394,237.58/666.47
  6. Step 6: Final answer
    x = 591.53

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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.