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Finding the Fourth Proportional to 774.20, 1,162.20 and 408.80

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Solution

The fourth proportional to 774.20, 1,162.20 and 408.80 is: 613.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    774.20 : 1,162.20 = 408.80 : x
  2. Step 2: Convert to fraction form
    774.20/1,162.20 = 408.80/x
  3. Step 3: Cross multiply
    774.20x = 1,162.20 × 408.80
  4. Step 4: Simplify right side
    774.20x = 475,107.36
  5. Step 5: Solve for x
    x = 475,107.36/774.20
  6. Step 6: Final answer
    x = 613.68

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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.