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Finding the Fourth Proportional to 220.89, 331.36 and 139.79

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Solution

The fourth proportional to 220.89, 331.36 and 139.79 is: 209.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.89 : 331.36 = 139.79 : x
  2. Step 2: Convert to fraction form
    220.89/331.36 = 139.79/x
  3. Step 3: Cross multiply
    220.89x = 331.36 × 139.79
  4. Step 4: Simplify right side
    220.89x = 46,321.29
  5. Step 5: Solve for x
    x = 46,321.29/220.89
  6. Step 6: Final answer
    x = 209.70

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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.