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Finding the Fourth Proportional to 381.20, 571.80 and 218.90

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Solution

The fourth proportional to 381.20, 571.80 and 218.90 is: 328.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.20 : 571.80 = 218.90 : x
  2. Step 2: Convert to fraction form
    381.20/571.80 = 218.90/x
  3. Step 3: Cross multiply
    381.20x = 571.80 × 218.90
  4. Step 4: Simplify right side
    381.20x = 125,167.02
  5. Step 5: Solve for x
    x = 125,167.02/381.20
  6. Step 6: Final answer
    x = 328.35

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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.