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Finding the Fourth Proportional to 20.77, 30.92 and 20.57

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Solution

The fourth proportional to 20.77, 30.92 and 20.57 is: 30.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.77 : 30.92 = 20.57 : x
  2. Step 2: Convert to fraction form
    20.77/30.92 = 20.57/x
  3. Step 3: Cross multiply
    20.77x = 30.92 × 20.57
  4. Step 4: Simplify right side
    20.77x = 635.77
  5. Step 5: Solve for x
    x = 635.77/20.77
  6. Step 6: Final answer
    x = 30.61

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.