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Finding the Fourth Proportional to 220.98, 304.89 and 138.21

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Solution

The fourth proportional to 220.98, 304.89 and 138.21 is: 190.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.98 : 304.89 = 138.21 : x
  2. Step 2: Convert to fraction form
    220.98/304.89 = 138.21/x
  3. Step 3: Cross multiply
    220.98x = 304.89 × 138.21
  4. Step 4: Simplify right side
    220.98x = 42,137.57
  5. Step 5: Solve for x
    x = 42,137.57/220.98
  6. Step 6: Final answer
    x = 190.69

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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.