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Finding the Fourth Proportional to 427.31, 640.90 and 119.19

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Solution

The fourth proportional to 427.31, 640.90 and 119.19 is: 178.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.31 : 640.90 = 119.19 : x
  2. Step 2: Convert to fraction form
    427.31/640.90 = 119.19/x
  3. Step 3: Cross multiply
    427.31x = 640.90 × 119.19
  4. Step 4: Simplify right side
    427.31x = 76,388.87
  5. Step 5: Solve for x
    x = 76,388.87/427.31
  6. Step 6: Final answer
    x = 178.77

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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.