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Finding the Fourth Proportional to 20.56, 30.90 and 17.86

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Solution

The fourth proportional to 20.56, 30.90 and 17.86 is: 26.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.56 : 30.90 = 17.86 : x
  2. Step 2: Convert to fraction form
    20.56/30.90 = 17.86/x
  3. Step 3: Cross multiply
    20.56x = 30.90 × 17.86
  4. Step 4: Simplify right side
    20.56x = 551.87
  5. Step 5: Solve for x
    x = 551.87/20.56
  6. Step 6: Final answer
    x = 26.84

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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.