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Finding the Fourth Proportional to 721.93, 996.21 and 407.20

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Solution

The fourth proportional to 721.93, 996.21 and 407.20 is: 561.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.93 : 996.21 = 407.20 : x
  2. Step 2: Convert to fraction form
    721.93/996.21 = 407.20/x
  3. Step 3: Cross multiply
    721.93x = 996.21 × 407.20
  4. Step 4: Simplify right side
    721.93x = 405,657.96
  5. Step 5: Solve for x
    x = 405,657.96/721.93
  6. Step 6: Final answer
    x = 561.91

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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.