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Finding the Fourth Proportional to 666.25, 998.87 and 391.97

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Solution

The fourth proportional to 666.25, 998.87 and 391.97 is: 587.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.25 : 998.87 = 391.97 : x
  2. Step 2: Convert to fraction form
    666.25/998.87 = 391.97/x
  3. Step 3: Cross multiply
    666.25x = 998.87 × 391.97
  4. Step 4: Simplify right side
    666.25x = 391,527.61
  5. Step 5: Solve for x
    x = 391,527.61/666.25
  6. Step 6: Final answer
    x = 587.66

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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.