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Finding the Fourth Proportional to 381.20, 515.10 and 381.20

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Solution

The fourth proportional to 381.20, 515.10 and 381.20 is: 515.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.20 : 515.10 = 381.20 : x
  2. Step 2: Convert to fraction form
    381.20/515.10 = 381.20/x
  3. Step 3: Cross multiply
    381.20x = 515.10 × 381.20
  4. Step 4: Simplify right side
    381.20x = 196,356.12
  5. Step 5: Solve for x
    x = 196,356.12/381.20
  6. Step 6: Final answer
    x = 515.10

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Why These Related Problems?

These problems maintain the same ratio (1.35) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.