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Finding the Fourth Proportional to 221.40, 305.24 and 138.47

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Solution

The fourth proportional to 221.40, 305.24 and 138.47 is: 190.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.40 : 305.24 = 138.47 : x
  2. Step 2: Convert to fraction form
    221.40/305.24 = 138.47/x
  3. Step 3: Cross multiply
    221.40x = 305.24 × 138.47
  4. Step 4: Simplify right side
    221.40x = 42,264.36
  5. Step 5: Solve for x
    x = 42,264.36/221.40
  6. Step 6: Final answer
    x = 190.90

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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.