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Finding the Fourth Proportional to 428.06, 642.09 and 119.94

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Solution

The fourth proportional to 428.06, 642.09 and 119.94 is: 179.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.06 : 642.09 = 119.94 : x
  2. Step 2: Convert to fraction form
    428.06/642.09 = 119.94/x
  3. Step 3: Cross multiply
    428.06x = 642.09 × 119.94
  4. Step 4: Simplify right side
    428.06x = 77,012.27
  5. Step 5: Solve for x
    x = 77,012.27/428.06
  6. Step 6: Final answer
    x = 179.91

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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.