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Finding the Fourth Proportional to 221.32, 305.45 and 138.45

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Solution

The fourth proportional to 221.32, 305.45 and 138.45 is: 191.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.32 : 305.45 = 138.45 : x
  2. Step 2: Convert to fraction form
    221.32/305.45 = 138.45/x
  3. Step 3: Cross multiply
    221.32x = 305.45 × 138.45
  4. Step 4: Simplify right side
    221.32x = 42,289.55
  5. Step 5: Solve for x
    x = 42,289.55/221.32
  6. Step 6: Final answer
    x = 191.08

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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.