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Finding the Fourth Proportional to 428.19, 642.15 and 168.12

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Solution

The fourth proportional to 428.19, 642.15 and 168.12 is: 252.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.19 : 642.15 = 168.12 : x
  2. Step 2: Convert to fraction form
    428.19/642.15 = 168.12/x
  3. Step 3: Cross multiply
    428.19x = 642.15 × 168.12
  4. Step 4: Simplify right side
    428.19x = 107,958.26
  5. Step 5: Solve for x
    x = 107,958.26/428.19
  6. Step 6: Final answer
    x = 252.13

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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.