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Finding the Fourth Proportional to 154.89, 212.85 and 128.97

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Solution

The fourth proportional to 154.89, 212.85 and 128.97 is: 177.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.89 : 212.85 = 128.97 : x
  2. Step 2: Convert to fraction form
    154.89/212.85 = 128.97/x
  3. Step 3: Cross multiply
    154.89x = 212.85 × 128.97
  4. Step 4: Simplify right side
    154.89x = 27,451.26
  5. Step 5: Solve for x
    x = 27,451.26/154.89
  6. Step 6: Final answer
    x = 177.23

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.