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Finding the Fourth Proportional to 693.21, 1,039.12 and 385.20

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Solution

The fourth proportional to 693.21, 1,039.12 and 385.20 is: 577.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    693.21 : 1,039.12 = 385.20 : x
  2. Step 2: Convert to fraction form
    693.21/1,039.12 = 385.20/x
  3. Step 3: Cross multiply
    693.21x = 1,039.12 × 385.20
  4. Step 4: Simplify right side
    693.21x = 400,262.87
  5. Step 5: Solve for x
    x = 400,262.87/693.21
  6. Step 6: Final answer
    x = 577.41

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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.