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Finding the Fourth Proportional to 682.15, 1,021.20 and 408.10

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Solution

The fourth proportional to 682.15, 1,021.20 and 408.10 is: 610.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    682.15 : 1,021.20 = 408.10 : x
  2. Step 2: Convert to fraction form
    682.15/1,021.20 = 408.10/x
  3. Step 3: Cross multiply
    682.15x = 1,021.20 × 408.10
  4. Step 4: Simplify right side
    682.15x = 416,751.72
  5. Step 5: Solve for x
    x = 416,751.72/682.15
  6. Step 6: Final answer
    x = 610.94

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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.