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Finding the Fourth Proportional to 521.07, 781.60 and 212.85

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Solution

The fourth proportional to 521.07, 781.60 and 212.85 is: 319.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.07 : 781.60 = 212.85 : x
  2. Step 2: Convert to fraction form
    521.07/781.60 = 212.85/x
  3. Step 3: Cross multiply
    521.07x = 781.60 × 212.85
  4. Step 4: Simplify right side
    521.07x = 166,363.56
  5. Step 5: Solve for x
    x = 166,363.56/521.07
  6. Step 6: Final answer
    x = 319.27

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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.