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Finding the Fourth Proportional to 128.28, 193.13 and 87.97

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Solution

The fourth proportional to 128.28, 193.13 and 87.97 is: 132.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.28 : 193.13 = 87.97 : x
  2. Step 2: Convert to fraction form
    128.28/193.13 = 87.97/x
  3. Step 3: Cross multiply
    128.28x = 193.13 × 87.97
  4. Step 4: Simplify right side
    128.28x = 16,989.91
  5. Step 5: Solve for x
    x = 16,989.91/128.28
  6. Step 6: Final answer
    x = 132.44

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.