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Finding the Fourth Proportional to 221.31, 331.42 and 156.21

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Solution

The fourth proportional to 221.31, 331.42 and 156.21 is: 233.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.31 : 331.42 = 156.21 : x
  2. Step 2: Convert to fraction form
    221.31/331.42 = 156.21/x
  3. Step 3: Cross multiply
    221.31x = 331.42 × 156.21
  4. Step 4: Simplify right side
    221.31x = 51,771.20
  5. Step 5: Solve for x
    x = 51,771.20/221.31
  6. Step 6: Final answer
    x = 233.93

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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.