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Finding the Fourth Proportional to 87.39, 130.13 and 86.37

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Solution

The fourth proportional to 87.39, 130.13 and 86.37 is: 128.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.39 : 130.13 = 86.37 : x
  2. Step 2: Convert to fraction form
    87.39/130.13 = 86.37/x
  3. Step 3: Cross multiply
    87.39x = 130.13 × 86.37
  4. Step 4: Simplify right side
    87.39x = 11,238.73
  5. Step 5: Solve for x
    x = 11,238.73/87.39
  6. Step 6: Final answer
    x = 128.60

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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.