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Finding the Fourth Proportional to 408.72, 609.48 and 391.84

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Solution

The fourth proportional to 408.72, 609.48 and 391.84 is: 584.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.72 : 609.48 = 391.84 : x
  2. Step 2: Convert to fraction form
    408.72/609.48 = 391.84/x
  3. Step 3: Cross multiply
    408.72x = 609.48 × 391.84
  4. Step 4: Simplify right side
    408.72x = 238,818.64
  5. Step 5: Solve for x
    x = 238,818.64/408.72
  6. Step 6: Final answer
    x = 584.31

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.