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Finding the Fourth Proportional to 428.05, 642.01 and 119.83

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Solution

The fourth proportional to 428.05, 642.01 and 119.83 is: 179.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.05 : 642.01 = 119.83 : x
  2. Step 2: Convert to fraction form
    428.05/642.01 = 119.83/x
  3. Step 3: Cross multiply
    428.05x = 642.01 × 119.83
  4. Step 4: Simplify right side
    428.05x = 76,932.06
  5. Step 5: Solve for x
    x = 76,932.06/428.05
  6. Step 6: Final answer
    x = 179.73

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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.