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Finding the Fourth Proportional to 20.90, 31.22 and 16.56

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Solution

The fourth proportional to 20.90, 31.22 and 16.56 is: 24.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.90 : 31.22 = 16.56 : x
  2. Step 2: Convert to fraction form
    20.90/31.22 = 16.56/x
  3. Step 3: Cross multiply
    20.90x = 31.22 × 16.56
  4. Step 4: Simplify right side
    20.90x = 517.00
  5. Step 5: Solve for x
    x = 517.00/20.90
  6. Step 6: Final answer
    x = 24.74

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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.