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Finding the Fourth Proportional to 51.42, 77.09 and 20.96

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Solution

The fourth proportional to 51.42, 77.09 and 20.96 is: 31.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.42 : 77.09 = 20.96 : x
  2. Step 2: Convert to fraction form
    51.42/77.09 = 20.96/x
  3. Step 3: Cross multiply
    51.42x = 77.09 × 20.96
  4. Step 4: Simplify right side
    51.42x = 1,615.42
  5. Step 5: Solve for x
    x = 1,615.42/51.42
  6. Step 6: Final answer
    x = 31.42

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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.