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Finding the Fourth Proportional to 86.99, 120.09 and 67.61

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Solution

The fourth proportional to 86.99, 120.09 and 67.61 is: 93.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.99 : 120.09 = 67.61 : x
  2. Step 2: Convert to fraction form
    86.99/120.09 = 67.61/x
  3. Step 3: Cross multiply
    86.99x = 120.09 × 67.61
  4. Step 4: Simplify right side
    86.99x = 8,119.28
  5. Step 5: Solve for x
    x = 8,119.28/86.99
  6. Step 6: Final answer
    x = 93.34

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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.