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Finding the Fourth Proportional to 154.50, 231.55 and 128.87

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Solution

The fourth proportional to 154.50, 231.55 and 128.87 is: 193.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.50 : 231.55 = 128.87 : x
  2. Step 2: Convert to fraction form
    154.50/231.55 = 128.87/x
  3. Step 3: Cross multiply
    154.50x = 231.55 × 128.87
  4. Step 4: Simplify right side
    154.50x = 29,839.49
  5. Step 5: Solve for x
    x = 29,839.49/154.50
  6. Step 6: Final answer
    x = 193.14

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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.