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Finding the Fourth Proportional to 86.94, 131.06 and 81.07

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Solution

The fourth proportional to 86.94, 131.06 and 81.07 is: 122.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.94 : 131.06 = 81.07 : x
  2. Step 2: Convert to fraction form
    86.94/131.06 = 81.07/x
  3. Step 3: Cross multiply
    86.94x = 131.06 × 81.07
  4. Step 4: Simplify right side
    86.94x = 10,625.03
  5. Step 5: Solve for x
    x = 10,625.03/86.94
  6. Step 6: Final answer
    x = 122.21

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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.