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Finding the Fourth Proportional to 728.92, 1,005.87 and 418.42

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Solution

The fourth proportional to 728.92, 1,005.87 and 418.42 is: 577.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.92 : 1,005.87 = 418.42 : x
  2. Step 2: Convert to fraction form
    728.92/1,005.87 = 418.42/x
  3. Step 3: Cross multiply
    728.92x = 1,005.87 × 418.42
  4. Step 4: Simplify right side
    728.92x = 420,876.13
  5. Step 5: Solve for x
    x = 420,876.13/728.92
  6. Step 6: Final answer
    x = 577.40

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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.