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Finding the Fourth Proportional to 609.67, 840.97 and 399.86

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Solution

The fourth proportional to 609.67, 840.97 and 399.86 is: 551.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.67 : 840.97 = 399.86 : x
  2. Step 2: Convert to fraction form
    609.67/840.97 = 399.86/x
  3. Step 3: Cross multiply
    609.67x = 840.97 × 399.86
  4. Step 4: Simplify right side
    609.67x = 336,267.46
  5. Step 5: Solve for x
    x = 336,267.46/609.67
  6. Step 6: Final answer
    x = 551.56

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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.