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Finding the Fourth Proportional to 20,806, 31,209 and 8,331.64

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Solution

The fourth proportional to 20,806, 31,209 and 8,331.64 is: 12,497.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    20,806 : 31,209 = 8,331.64 : x
  2. Step 2: Convert to fraction form
    20,806/31,209 = 8,331.64/x
  3. Step 3: Cross multiply
    20,806x = 31,209 × 8,331.64
  4. Step 4: Simplify right side
    20,806x = 260,022,152.76
  5. Step 5: Solve for x
    x = 260,022,152.76/20,806
  6. Step 6: Final answer
    x = 12,497.46

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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.