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Finding the Fourth Proportional to 86.45, 118.41 and 81.47

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Solution

The fourth proportional to 86.45, 118.41 and 81.47 is: 111.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.45 : 118.41 = 81.47 : x
  2. Step 2: Convert to fraction form
    86.45/118.41 = 81.47/x
  3. Step 3: Cross multiply
    86.45x = 118.41 × 81.47
  4. Step 4: Simplify right side
    86.45x = 9,646.27
  5. Step 5: Solve for x
    x = 9,646.27/86.45
  6. Step 6: Final answer
    x = 111.59

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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.