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Finding the Fourth Proportional to 82.05, 122.90 and 38.66

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Solution

The fourth proportional to 82.05, 122.90 and 38.66 is: 57.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.05 : 122.90 = 38.66 : x
  2. Step 2: Convert to fraction form
    82.05/122.90 = 38.66/x
  3. Step 3: Cross multiply
    82.05x = 122.90 × 38.66
  4. Step 4: Simplify right side
    82.05x = 4,750.89
  5. Step 5: Solve for x
    x = 4,750.89/82.05
  6. Step 6: Final answer
    x = 57.90

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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.