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Finding the Fourth Proportional to 87.04, 129.92 and 86.08

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Solution

The fourth proportional to 87.04, 129.92 and 86.08 is: 128.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.04 : 129.92 = 86.08 : x
  2. Step 2: Convert to fraction form
    87.04/129.92 = 86.08/x
  3. Step 3: Cross multiply
    87.04x = 129.92 × 86.08
  4. Step 4: Simplify right side
    87.04x = 11,183.51
  5. Step 5: Solve for x
    x = 11,183.51/87.04
  6. Step 6: Final answer
    x = 128.49

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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.