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Finding the Fourth Proportional to 51.81, 77.69 and 31.56

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Solution

The fourth proportional to 51.81, 77.69 and 31.56 is: 47.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.81 : 77.69 = 31.56 : x
  2. Step 2: Convert to fraction form
    51.81/77.69 = 31.56/x
  3. Step 3: Cross multiply
    51.81x = 77.69 × 31.56
  4. Step 4: Simplify right side
    51.81x = 2,451.90
  5. Step 5: Solve for x
    x = 2,451.90/51.81
  6. Step 6: Final answer
    x = 47.32

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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.