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Finding the Fourth Proportional to 221.27, 305.42 and 138.45

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Solution

The fourth proportional to 221.27, 305.42 and 138.45 is: 191.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.27 : 305.42 = 138.45 : x
  2. Step 2: Convert to fraction form
    221.27/305.42 = 138.45/x
  3. Step 3: Cross multiply
    221.27x = 305.42 × 138.45
  4. Step 4: Simplify right side
    221.27x = 42,285.40
  5. Step 5: Solve for x
    x = 42,285.40/221.27
  6. Step 6: Final answer
    x = 191.10

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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.