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Finding the Fourth Proportional to 47.96, 71.96 and 20.90

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Solution

The fourth proportional to 47.96, 71.96 and 20.90 is: 31.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.96 : 71.96 = 20.90 : x
  2. Step 2: Convert to fraction form
    47.96/71.96 = 20.90/x
  3. Step 3: Cross multiply
    47.96x = 71.96 × 20.90
  4. Step 4: Simplify right side
    47.96x = 1,503.96
  5. Step 5: Solve for x
    x = 1,503.96/47.96
  6. Step 6: Final answer
    x = 31.36

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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.