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Finding the Fourth Proportional to 86.12, 117.80 and 85.85

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Solution

The fourth proportional to 86.12, 117.80 and 85.85 is: 117.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.12 : 117.80 = 85.85 : x
  2. Step 2: Convert to fraction form
    86.12/117.80 = 85.85/x
  3. Step 3: Cross multiply
    86.12x = 117.80 × 85.85
  4. Step 4: Simplify right side
    86.12x = 10,112.11
  5. Step 5: Solve for x
    x = 10,112.11/86.12
  6. Step 6: Final answer
    x = 117.43

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.