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Finding the Fourth Proportional to 87.12, 131.14 and 79.68

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Solution

The fourth proportional to 87.12, 131.14 and 79.68 is: 119.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.12 : 131.14 = 79.68 : x
  2. Step 2: Convert to fraction form
    87.12/131.14 = 79.68/x
  3. Step 3: Cross multiply
    87.12x = 131.14 × 79.68
  4. Step 4: Simplify right side
    87.12x = 10,449.24
  5. Step 5: Solve for x
    x = 10,449.24/87.12
  6. Step 6: Final answer
    x = 119.94

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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.