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Finding the Fourth Proportional to 723.78, 1,086.75 and 399.78

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Solution

The fourth proportional to 723.78, 1,086.75 and 399.78 is: 600.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    723.78 : 1,086.75 = 399.78 : x
  2. Step 2: Convert to fraction form
    723.78/1,086.75 = 399.78/x
  3. Step 3: Cross multiply
    723.78x = 1,086.75 × 399.78
  4. Step 4: Simplify right side
    723.78x = 434,460.92
  5. Step 5: Solve for x
    x = 434,460.92/723.78
  6. Step 6: Final answer
    x = 600.27

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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.