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Finding the Fourth Proportional to 51.29, 76.87 and 20.82

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Solution

The fourth proportional to 51.29, 76.87 and 20.82 is: 31.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.29 : 76.87 = 20.82 : x
  2. Step 2: Convert to fraction form
    51.29/76.87 = 20.82/x
  3. Step 3: Cross multiply
    51.29x = 76.87 × 20.82
  4. Step 4: Simplify right side
    51.29x = 1,600.43
  5. Step 5: Solve for x
    x = 1,600.43/51.29
  6. Step 6: Final answer
    x = 31.20

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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.