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Finding the Fourth Proportional to 721.89, 1,083.42 and 289.35

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Solution

The fourth proportional to 721.89, 1,083.42 and 289.35 is: 434.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.89 : 1,083.42 = 289.35 : x
  2. Step 2: Convert to fraction form
    721.89/1,083.42 = 289.35/x
  3. Step 3: Cross multiply
    721.89x = 1,083.42 × 289.35
  4. Step 4: Simplify right side
    721.89x = 313,487.58
  5. Step 5: Solve for x
    x = 313,487.58/721.89
  6. Step 6: Final answer
    x = 434.26

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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.