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Finding the Fourth Proportional to 5,200, 7,800 and 2,081.40

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Solution

The fourth proportional to 5,200, 7,800 and 2,081.40 is: 3,122.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    5,200 : 7,800 = 2,081.40 : x
  2. Step 2: Convert to fraction form
    5,200/7,800 = 2,081.40/x
  3. Step 3: Cross multiply
    5,200x = 7,800 × 2,081.40
  4. Step 4: Simplify right side
    5,200x = 16,234,920
  5. Step 5: Solve for x
    x = 16,234,920/5,200
  6. Step 6: Final answer
    x = 3,122.10

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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.