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Finding the Fourth Proportional to 220.32, 330.12 and 138.90

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Solution

The fourth proportional to 220.32, 330.12 and 138.90 is: 208.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.32 : 330.12 = 138.90 : x
  2. Step 2: Convert to fraction form
    220.32/330.12 = 138.90/x
  3. Step 3: Cross multiply
    220.32x = 330.12 × 138.90
  4. Step 4: Simplify right side
    220.32x = 45,853.67
  5. Step 5: Solve for x
    x = 45,853.67/220.32
  6. Step 6: Final answer
    x = 208.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.