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Finding the Fourth Proportional to 429.92, 645.40 and 408.38

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Solution

The fourth proportional to 429.92, 645.40 and 408.38 is: 613.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.92 : 645.40 = 408.38 : x
  2. Step 2: Convert to fraction form
    429.92/645.40 = 408.38/x
  3. Step 3: Cross multiply
    429.92x = 645.40 × 408.38
  4. Step 4: Simplify right side
    429.92x = 263,568.45
  5. Step 5: Solve for x
    x = 263,568.45/429.92
  6. Step 6: Final answer
    x = 613.06

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.