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Finding the Fourth Proportional to 221.30, 305.38 and 138.43

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Solution

The fourth proportional to 221.30, 305.38 and 138.43 is: 191.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.30 : 305.38 = 138.43 : x
  2. Step 2: Convert to fraction form
    221.30/305.38 = 138.43/x
  3. Step 3: Cross multiply
    221.30x = 305.38 × 138.43
  4. Step 4: Simplify right side
    221.30x = 42,273.75
  5. Step 5: Solve for x
    x = 42,273.75/221.30
  6. Step 6: Final answer
    x = 191.02

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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.