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Finding the Fourth Proportional to 511.21, 765.60 and 408.58

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Solution

The fourth proportional to 511.21, 765.60 and 408.58 is: 611.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    511.21 : 765.60 = 408.58 : x
  2. Step 2: Convert to fraction form
    511.21/765.60 = 408.58/x
  3. Step 3: Cross multiply
    511.21x = 765.60 × 408.58
  4. Step 4: Simplify right side
    511.21x = 312,808.85
  5. Step 5: Solve for x
    x = 312,808.85/511.21
  6. Step 6: Final answer
    x = 611.90

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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.