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Finding the Fourth Proportional to 81.63, 121.89 and 63.54

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Solution

The fourth proportional to 81.63, 121.89 and 63.54 is: 94.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.63 : 121.89 = 63.54 : x
  2. Step 2: Convert to fraction form
    81.63/121.89 = 63.54/x
  3. Step 3: Cross multiply
    81.63x = 121.89 × 63.54
  4. Step 4: Simplify right side
    81.63x = 7,744.89
  5. Step 5: Solve for x
    x = 7,744.89/81.63
  6. Step 6: Final answer
    x = 94.88

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.