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Finding the Fourth Proportional to 21.41, 29.75 and 20.91

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Solution

The fourth proportional to 21.41, 29.75 and 20.91 is: 29.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.41 : 29.75 = 20.91 : x
  2. Step 2: Convert to fraction form
    21.41/29.75 = 20.91/x
  3. Step 3: Cross multiply
    21.41x = 29.75 × 20.91
  4. Step 4: Simplify right side
    21.41x = 621.97
  5. Step 5: Solve for x
    x = 621.97/21.41
  6. Step 6: Final answer
    x = 29.06

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.