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Finding the Fourth Proportional to 20.82, 31.34 and 19.66

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Solution

The fourth proportional to 20.82, 31.34 and 19.66 is: 29.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.82 : 31.34 = 19.66 : x
  2. Step 2: Convert to fraction form
    20.82/31.34 = 19.66/x
  3. Step 3: Cross multiply
    20.82x = 31.34 × 19.66
  4. Step 4: Simplify right side
    20.82x = 616.14
  5. Step 5: Solve for x
    x = 616.14/20.82
  6. Step 6: Final answer
    x = 29.59

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.