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Finding the Fourth Proportional to 220.25, 330.36 and 128.76

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Solution

The fourth proportional to 220.25, 330.36 and 128.76 is: 193.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.25 : 330.36 = 128.76 : x
  2. Step 2: Convert to fraction form
    220.25/330.36 = 128.76/x
  3. Step 3: Cross multiply
    220.25x = 330.36 × 128.76
  4. Step 4: Simplify right side
    220.25x = 42,537.15
  5. Step 5: Solve for x
    x = 42,537.15/220.25
  6. Step 6: Final answer
    x = 193.13

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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.