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Finding the Fourth Proportional to 429.39, 639.15 and 409.47

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Solution

The fourth proportional to 429.39, 639.15 and 409.47 is: 609.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.39 : 639.15 = 409.47 : x
  2. Step 2: Convert to fraction form
    429.39/639.15 = 409.47/x
  3. Step 3: Cross multiply
    429.39x = 639.15 × 409.47
  4. Step 4: Simplify right side
    429.39x = 261,712.75
  5. Step 5: Solve for x
    x = 261,712.75/429.39
  6. Step 6: Final answer
    x = 609.50

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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.