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Finding the Fourth Proportional to 81.42, 122.14 and 52.55

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Solution

The fourth proportional to 81.42, 122.14 and 52.55 is: 78.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.42 : 122.14 = 52.55 : x
  2. Step 2: Convert to fraction form
    81.42/122.14 = 52.55/x
  3. Step 3: Cross multiply
    81.42x = 122.14 × 52.55
  4. Step 4: Simplify right side
    81.42x = 6,418.17
  5. Step 5: Solve for x
    x = 6,418.17/81.42
  6. Step 6: Final answer
    x = 78.82

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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.