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Finding the Fourth Proportional to 81.77, 122.45 and 54.63

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Solution

The fourth proportional to 81.77, 122.45 and 54.63 is: 81.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.77 : 122.45 = 54.63 : x
  2. Step 2: Convert to fraction form
    81.77/122.45 = 54.63/x
  3. Step 3: Cross multiply
    81.77x = 122.45 × 54.63
  4. Step 4: Simplify right side
    81.77x = 6,689.17
  5. Step 5: Solve for x
    x = 6,689.17/81.77
  6. Step 6: Final answer
    x = 81.81

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.