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Finding the Fourth Proportional to 428.88, 642.87 and 168.81

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Solution

The fourth proportional to 428.88, 642.87 and 168.81 is: 253.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.88 : 642.87 = 168.81 : x
  2. Step 2: Convert to fraction form
    428.88/642.87 = 168.81/x
  3. Step 3: Cross multiply
    428.88x = 642.87 × 168.81
  4. Step 4: Simplify right side
    428.88x = 108,522.88
  5. Step 5: Solve for x
    x = 108,522.88/428.88
  6. Step 6: Final answer
    x = 253.04

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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.