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Finding the Fourth Proportional to 428.39, 642.45 and 168.38

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Solution

The fourth proportional to 428.39, 642.45 and 168.38 is: 252.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.39 : 642.45 = 168.38 : x
  2. Step 2: Convert to fraction form
    428.39/642.45 = 168.38/x
  3. Step 3: Cross multiply
    428.39x = 642.45 × 168.38
  4. Step 4: Simplify right side
    428.39x = 108,175.73
  5. Step 5: Solve for x
    x = 108,175.73/428.39
  6. Step 6: Final answer
    x = 252.52

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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.