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Finding the Fourth Proportional to 221.62, 305.66 and 138.64

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Solution

The fourth proportional to 221.62, 305.66 and 138.64 is: 191.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.62 : 305.66 = 138.64 : x
  2. Step 2: Convert to fraction form
    221.62/305.66 = 138.64/x
  3. Step 3: Cross multiply
    221.62x = 305.66 × 138.64
  4. Step 4: Simplify right side
    221.62x = 42,376.70
  5. Step 5: Solve for x
    x = 42,376.70/221.62
  6. Step 6: Final answer
    x = 191.21

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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.