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Finding the Fourth Proportional to 511.91, 767.90 and 390.92

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Solution

The fourth proportional to 511.91, 767.90 and 390.92 is: 586.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    511.91 : 767.90 = 390.92 : x
  2. Step 2: Convert to fraction form
    511.91/767.90 = 390.92/x
  3. Step 3: Cross multiply
    511.91x = 767.90 × 390.92
  4. Step 4: Simplify right side
    511.91x = 300,181.67
  5. Step 5: Solve for x
    x = 300,181.67/511.91
  6. Step 6: Final answer
    x = 586.39

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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.