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Finding the Fourth Proportional to 97.81, 134.87 and 86.87

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Solution

The fourth proportional to 97.81, 134.87 and 86.87 is: 119.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    97.81 : 134.87 = 86.87 : x
  2. Step 2: Convert to fraction form
    97.81/134.87 = 86.87/x
  3. Step 3: Cross multiply
    97.81x = 134.87 × 86.87
  4. Step 4: Simplify right side
    97.81x = 11,716.06
  5. Step 5: Solve for x
    x = 11,716.06/97.81
  6. Step 6: Final answer
    x = 119.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.