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Finding the Fourth Proportional to 429.13, 639.30 and 408.49

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Solution

The fourth proportional to 429.13, 639.30 and 408.49 is: 608.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.13 : 639.30 = 408.49 : x
  2. Step 2: Convert to fraction form
    429.13/639.30 = 408.49/x
  3. Step 3: Cross multiply
    429.13x = 639.30 × 408.49
  4. Step 4: Simplify right side
    429.13x = 261,147.66
  5. Step 5: Solve for x
    x = 261,147.66/429.13
  6. Step 6: Final answer
    x = 608.55

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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.