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Finding the Fourth Proportional to 3,969, 5,481.80 and 2,640.40

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Solution

The fourth proportional to 3,969, 5,481.80 and 2,640.40 is: 3,646.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,969 : 5,481.80 = 2,640.40 : x
  2. Step 2: Convert to fraction form
    3,969/5,481.80 = 2,640.40/x
  3. Step 3: Cross multiply
    3,969x = 5,481.80 × 2,640.40
  4. Step 4: Simplify right side
    3,969x = 14,474,144.72
  5. Step 5: Solve for x
    x = 14,474,144.72/3,969
  6. Step 6: Final answer
    x = 3,646.80

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.