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Finding the Fourth Proportional to 513.62, 708.78 and 280.74

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Solution

The fourth proportional to 513.62, 708.78 and 280.74 is: 387.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    513.62 : 708.78 = 280.74 : x
  2. Step 2: Convert to fraction form
    513.62/708.78 = 280.74/x
  3. Step 3: Cross multiply
    513.62x = 708.78 × 280.74
  4. Step 4: Simplify right side
    513.62x = 198,982.90
  5. Step 5: Solve for x
    x = 198,982.90/513.62
  6. Step 6: Final answer
    x = 387.42

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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.