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Finding the Fourth Proportional to 87.10, 131.48 and 86.65

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Solution

The fourth proportional to 87.10, 131.48 and 86.65 is: 130.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.10 : 131.48 = 86.65 : x
  2. Step 2: Convert to fraction form
    87.10/131.48 = 86.65/x
  3. Step 3: Cross multiply
    87.10x = 131.48 × 86.65
  4. Step 4: Simplify right side
    87.10x = 11,392.74
  5. Step 5: Solve for x
    x = 11,392.74/87.10
  6. Step 6: Final answer
    x = 130.80

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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.