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Finding the Fourth Proportional to 685.05, 945.31 and 405.27

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Solution

The fourth proportional to 685.05, 945.31 and 405.27 is: 559.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.05 : 945.31 = 405.27 : x
  2. Step 2: Convert to fraction form
    685.05/945.31 = 405.27/x
  3. Step 3: Cross multiply
    685.05x = 945.31 × 405.27
  4. Step 4: Simplify right side
    685.05x = 383,105.78
  5. Step 5: Solve for x
    x = 383,105.78/685.05
  6. Step 6: Final answer
    x = 559.24

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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.