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Finding the Fourth Proportional to 87.36, 130.32 and 81.84

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Solution

The fourth proportional to 87.36, 130.32 and 81.84 is: 122.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.36 : 130.32 = 81.84 : x
  2. Step 2: Convert to fraction form
    87.36/130.32 = 81.84/x
  3. Step 3: Cross multiply
    87.36x = 130.32 × 81.84
  4. Step 4: Simplify right side
    87.36x = 10,665.39
  5. Step 5: Solve for x
    x = 10,665.39/87.36
  6. Step 6: Final answer
    x = 122.09

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.