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Finding the Fourth Proportional to 222.20, 306.65 and 128.95

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Solution

The fourth proportional to 222.20, 306.65 and 128.95 is: 177.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    222.20 : 306.65 = 128.95 : x
  2. Step 2: Convert to fraction form
    222.20/306.65 = 128.95/x
  3. Step 3: Cross multiply
    222.20x = 306.65 × 128.95
  4. Step 4: Simplify right side
    222.20x = 39,542.52
  5. Step 5: Solve for x
    x = 39,542.52/222.20
  6. Step 6: Final answer
    x = 177.96

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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.