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Finding the Fourth Proportional to 728.72, 1,092.36 and 386

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Solution

The fourth proportional to 728.72, 1,092.36 and 386 is: 578.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.72 : 1,092.36 = 386 : x
  2. Step 2: Convert to fraction form
    728.72/1,092.36 = 386/x
  3. Step 3: Cross multiply
    728.72x = 1,092.36 × 386
  4. Step 4: Simplify right side
    728.72x = 421,650.96
  5. Step 5: Solve for x
    x = 421,650.96/728.72
  6. Step 6: Final answer
    x = 578.62

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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.