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Finding the Fourth Proportional to 81.45, 112.28 and 66.87

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Solution

The fourth proportional to 81.45, 112.28 and 66.87 is: 92.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.45 : 112.28 = 66.87 : x
  2. Step 2: Convert to fraction form
    81.45/112.28 = 66.87/x
  3. Step 3: Cross multiply
    81.45x = 112.28 × 66.87
  4. Step 4: Simplify right side
    81.45x = 7,507.83
  5. Step 5: Solve for x
    x = 7,507.83/81.45
  6. Step 6: Final answer
    x = 92.18

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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.