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Finding the Fourth Proportional to 428.88, 638.40 and 408.97

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Solution

The fourth proportional to 428.88, 638.40 and 408.97 is: 608.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.88 : 638.40 = 408.97 : x
  2. Step 2: Convert to fraction form
    428.88/638.40 = 408.97/x
  3. Step 3: Cross multiply
    428.88x = 638.40 × 408.97
  4. Step 4: Simplify right side
    428.88x = 261,086.45
  5. Step 5: Solve for x
    x = 261,086.45/428.88
  6. Step 6: Final answer
    x = 608.76

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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.