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Finding the Fourth Proportional to 2,620.20, 3,930 and 771.56

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Solution

The fourth proportional to 2,620.20, 3,930 and 771.56 is: 1,157.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,620.20 : 3,930 = 771.56 : x
  2. Step 2: Convert to fraction form
    2,620.20/3,930 = 771.56/x
  3. Step 3: Cross multiply
    2,620.20x = 3,930 × 771.56
  4. Step 4: Simplify right side
    2,620.20x = 3,032,230.80
  5. Step 5: Solve for x
    x = 3,032,230.80/2,620.20
  6. Step 6: Final answer
    x = 1,157.25

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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.