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Finding the Fourth Proportional to 221.38, 305.48 and 121.79

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Solution

The fourth proportional to 221.38, 305.48 and 121.79 is: 168.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.38 : 305.48 = 121.79 : x
  2. Step 2: Convert to fraction form
    221.38/305.48 = 121.79/x
  3. Step 3: Cross multiply
    221.38x = 305.48 × 121.79
  4. Step 4: Simplify right side
    221.38x = 37,203.57
  5. Step 5: Solve for x
    x = 37,203.57/221.38
  6. Step 6: Final answer
    x = 168.06

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.