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Finding the Fourth Proportional to 221.48, 305.60 and 138.56

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Solution

The fourth proportional to 221.48, 305.60 and 138.56 is: 191.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.48 : 305.60 = 138.56 : x
  2. Step 2: Convert to fraction form
    221.48/305.60 = 138.56/x
  3. Step 3: Cross multiply
    221.48x = 305.60 × 138.56
  4. Step 4: Simplify right side
    221.48x = 42,343.94
  5. Step 5: Solve for x
    x = 42,343.94/221.48
  6. Step 6: Final answer
    x = 191.19

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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.