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Finding the Fourth Proportional to 20.77, 31.19 and 17.91

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Solution

The fourth proportional to 20.77, 31.19 and 17.91 is: 26.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.77 : 31.19 = 17.91 : x
  2. Step 2: Convert to fraction form
    20.77/31.19 = 17.91/x
  3. Step 3: Cross multiply
    20.77x = 31.19 × 17.91
  4. Step 4: Simplify right side
    20.77x = 558.61
  5. Step 5: Solve for x
    x = 558.61/20.77
  6. Step 6: Final answer
    x = 26.90

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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.