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Finding the Fourth Proportional to 609.38, 840.64 and 388.39

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Solution

The fourth proportional to 609.38, 840.64 and 388.39 is: 535.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.38 : 840.64 = 388.39 : x
  2. Step 2: Convert to fraction form
    609.38/840.64 = 388.39/x
  3. Step 3: Cross multiply
    609.38x = 840.64 × 388.39
  4. Step 4: Simplify right side
    609.38x = 326,496.17
  5. Step 5: Solve for x
    x = 326,496.17/609.38
  6. Step 6: Final answer
    x = 535.78

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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.