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Finding the Fourth Proportional to 521.11, 781.15 and 213.05

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Solution

The fourth proportional to 521.11, 781.15 and 213.05 is: 319.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.11 : 781.15 = 213.05 : x
  2. Step 2: Convert to fraction form
    521.11/781.15 = 213.05/x
  3. Step 3: Cross multiply
    521.11x = 781.15 × 213.05
  4. Step 4: Simplify right side
    521.11x = 166,426.49
  5. Step 5: Solve for x
    x = 166,426.49/521.11
  6. Step 6: Final answer
    x = 319.37

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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.