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Finding the Fourth Proportional to 728.90, 1,092.34 and 381.56

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Solution

The fourth proportional to 728.90, 1,092.34 and 381.56 is: 571.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.90 : 1,092.34 = 381.56 : x
  2. Step 2: Convert to fraction form
    728.90/1,092.34 = 381.56/x
  3. Step 3: Cross multiply
    728.90x = 1,092.34 × 381.56
  4. Step 4: Simplify right side
    728.90x = 416,793.25
  5. Step 5: Solve for x
    x = 416,793.25/728.90
  6. Step 6: Final answer
    x = 571.81

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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.