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Finding the Fourth Proportional to 428.17, 642.43 and 254.92

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Solution

The fourth proportional to 428.17, 642.43 and 254.92 is: 382.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.17 : 642.43 = 254.92 : x
  2. Step 2: Convert to fraction form
    428.17/642.43 = 254.92/x
  3. Step 3: Cross multiply
    428.17x = 642.43 × 254.92
  4. Step 4: Simplify right side
    428.17x = 163,769.98
  5. Step 5: Solve for x
    x = 163,769.98/428.17
  6. Step 6: Final answer
    x = 382.49

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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.