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Finding the Fourth Proportional to 520.39, 779.90 and 211.88

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Solution

The fourth proportional to 520.39, 779.90 and 211.88 is: 317.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.39 : 779.90 = 211.88 : x
  2. Step 2: Convert to fraction form
    520.39/779.90 = 211.88/x
  3. Step 3: Cross multiply
    520.39x = 779.90 × 211.88
  4. Step 4: Simplify right side
    520.39x = 165,241.84
  5. Step 5: Solve for x
    x = 165,241.84/520.39
  6. Step 6: Final answer
    x = 317.54

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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.