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Finding the Fourth Proportional to 7,980.78, 11,971.20 and 2,137.20

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Solution

The fourth proportional to 7,980.78, 11,971.20 and 2,137.20 is: 3,205.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    7,980.78 : 11,971.20 = 2,137.20 : x
  2. Step 2: Convert to fraction form
    7,980.78/11,971.20 = 2,137.20/x
  3. Step 3: Cross multiply
    7,980.78x = 11,971.20 × 2,137.20
  4. Step 4: Simplify right side
    7,980.78x = 25,584,848.64
  5. Step 5: Solve for x
    x = 25,584,848.64/7,980.78
  6. Step 6: Final answer
    x = 3,205.81

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1.5x scale

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.