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Finding the Fourth Proportional to 43.38, 65.12 and 20.61

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Solution

The fourth proportional to 43.38, 65.12 and 20.61 is: 30.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    43.38 : 65.12 = 20.61 : x
  2. Step 2: Convert to fraction form
    43.38/65.12 = 20.61/x
  3. Step 3: Cross multiply
    43.38x = 65.12 × 20.61
  4. Step 4: Simplify right side
    43.38x = 1,342.02
  5. Step 5: Solve for x
    x = 1,342.02/43.38
  6. Step 6: Final answer
    x = 30.94

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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.