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Finding the Fourth Proportional to 86.97, 119.99 and 85.17

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Solution

The fourth proportional to 86.97, 119.99 and 85.17 is: 117.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.97 : 119.99 = 85.17 : x
  2. Step 2: Convert to fraction form
    86.97/119.99 = 85.17/x
  3. Step 3: Cross multiply
    86.97x = 119.99 × 85.17
  4. Step 4: Simplify right side
    86.97x = 10,219.12
  5. Step 5: Solve for x
    x = 10,219.12/86.97
  6. Step 6: Final answer
    x = 117.50

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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.