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Finding the Fourth Proportional to 81.82, 122.71 and 30.45

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Solution

The fourth proportional to 81.82, 122.71 and 30.45 is: 45.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.82 : 122.71 = 30.45 : x
  2. Step 2: Convert to fraction form
    81.82/122.71 = 30.45/x
  3. Step 3: Cross multiply
    81.82x = 122.71 × 30.45
  4. Step 4: Simplify right side
    81.82x = 3,736.52
  5. Step 5: Solve for x
    x = 3,736.52/81.82
  6. Step 6: Final answer
    x = 45.67

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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.