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Finding the Fourth Proportional to 221.09, 331.61 and 91.06

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Solution

The fourth proportional to 221.09, 331.61 and 91.06 is: 136.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.09 : 331.61 = 91.06 : x
  2. Step 2: Convert to fraction form
    221.09/331.61 = 91.06/x
  3. Step 3: Cross multiply
    221.09x = 331.61 × 91.06
  4. Step 4: Simplify right side
    221.09x = 30,195.12
  5. Step 5: Solve for x
    x = 30,195.12/221.09
  6. Step 6: Final answer
    x = 136.58

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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.