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Finding the Fourth Proportional to 721.98, 996.91 and 666.70

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Solution

The fourth proportional to 721.98, 996.91 and 666.70 is: 920.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.98 : 996.91 = 666.70 : x
  2. Step 2: Convert to fraction form
    721.98/996.91 = 666.70/x
  3. Step 3: Cross multiply
    721.98x = 996.91 × 666.70
  4. Step 4: Simplify right side
    721.98x = 664,635.74
  5. Step 5: Solve for x
    x = 664,635.74/721.98
  6. Step 6: Final answer
    x = 920.57

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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.