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Finding the Fourth Proportional to 154.95, 213.69 and 128.73

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Solution

The fourth proportional to 154.95, 213.69 and 128.73 is: 177.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.95 : 213.69 = 128.73 : x
  2. Step 2: Convert to fraction form
    154.95/213.69 = 128.73/x
  3. Step 3: Cross multiply
    154.95x = 213.69 × 128.73
  4. Step 4: Simplify right side
    154.95x = 27,508.31
  5. Step 5: Solve for x
    x = 27,508.31/154.95
  6. Step 6: Final answer
    x = 177.53

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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.