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Finding the Fourth Proportional to 221.19, 331.71 and 76.89

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Solution

The fourth proportional to 221.19, 331.71 and 76.89 is: 115.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.19 : 331.71 = 76.89 : x
  2. Step 2: Convert to fraction form
    221.19/331.71 = 76.89/x
  3. Step 3: Cross multiply
    221.19x = 331.71 × 76.89
  4. Step 4: Simplify right side
    221.19x = 25,505.18
  5. Step 5: Solve for x
    x = 25,505.18/221.19
  6. Step 6: Final answer
    x = 115.31

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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.