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Finding the Fourth Proportional to 519.90, 780.17 and 211.76

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Solution

The fourth proportional to 519.90, 780.17 and 211.76 is: 317.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    519.90 : 780.17 = 211.76 : x
  2. Step 2: Convert to fraction form
    519.90/780.17 = 211.76/x
  3. Step 3: Cross multiply
    519.90x = 780.17 × 211.76
  4. Step 4: Simplify right side
    519.90x = 165,203.84
  5. Step 5: Solve for x
    x = 165,203.84/519.90
  6. Step 6: Final answer
    x = 317.76

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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.