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Finding the Fourth Proportional to 220.72, 331 and 90.71

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Solution

The fourth proportional to 220.72, 331 and 90.71 is: 136.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.72 : 331 = 90.71 : x
  2. Step 2: Convert to fraction form
    220.72/331 = 90.71/x
  3. Step 3: Cross multiply
    220.72x = 331 × 90.71
  4. Step 4: Simplify right side
    220.72x = 30,025.01
  5. Step 5: Solve for x
    x = 30,025.01/220.72
  6. Step 6: Final answer
    x = 136.03

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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.