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Finding the Fourth Proportional to 645.39, 966.78 and 515.61

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Solution

The fourth proportional to 645.39, 966.78 and 515.61 is: 772.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.39 : 966.78 = 515.61 : x
  2. Step 2: Convert to fraction form
    645.39/966.78 = 515.61/x
  3. Step 3: Cross multiply
    645.39x = 966.78 × 515.61
  4. Step 4: Simplify right side
    645.39x = 498,481.44
  5. Step 5: Solve for x
    x = 498,481.44/645.39
  6. Step 6: Final answer
    x = 772.37

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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.