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Finding the Fourth Proportional to 521.43, 782.13 and 213.21

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Solution

The fourth proportional to 521.43, 782.13 and 213.21 is: 319.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.43 : 782.13 = 213.21 : x
  2. Step 2: Convert to fraction form
    521.43/782.13 = 213.21/x
  3. Step 3: Cross multiply
    521.43x = 782.13 × 213.21
  4. Step 4: Simplify right side
    521.43x = 166,757.54
  5. Step 5: Solve for x
    x = 166,757.54/521.43
  6. Step 6: Final answer
    x = 319.81

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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.