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Finding the Fourth Proportional to 81.57, 122.10 and 54.16

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Solution

The fourth proportional to 81.57, 122.10 and 54.16 is: 81.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.57 : 122.10 = 54.16 : x
  2. Step 2: Convert to fraction form
    81.57/122.10 = 54.16/x
  3. Step 3: Cross multiply
    81.57x = 122.10 × 54.16
  4. Step 4: Simplify right side
    81.57x = 6,612.94
  5. Step 5: Solve for x
    x = 6,612.94/81.57
  6. Step 6: Final answer
    x = 81.07

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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.