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Finding the Fourth Proportional to 513.76, 709 and 280.90

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Solution

The fourth proportional to 513.76, 709 and 280.90 is: 387.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    513.76 : 709 = 280.90 : x
  2. Step 2: Convert to fraction form
    513.76/709 = 280.90/x
  3. Step 3: Cross multiply
    513.76x = 709 × 280.90
  4. Step 4: Simplify right side
    513.76x = 199,158.10
  5. Step 5: Solve for x
    x = 199,158.10/513.76
  6. Step 6: Final answer
    x = 387.65

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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.