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Finding the Fourth Proportional to 21.81, 32.67 and 20.97

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Solution

The fourth proportional to 21.81, 32.67 and 20.97 is: 31.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.81 : 32.67 = 20.97 : x
  2. Step 2: Convert to fraction form
    21.81/32.67 = 20.97/x
  3. Step 3: Cross multiply
    21.81x = 32.67 × 20.97
  4. Step 4: Simplify right side
    21.81x = 684.93
  5. Step 5: Solve for x
    x = 684.93/21.81
  6. Step 6: Final answer
    x = 31.41

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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.