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Finding the Fourth Proportional to 413.70, 619.20 and 321.90

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Solution

The fourth proportional to 413.70, 619.20 and 321.90 is: 481.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    413.70 : 619.20 = 321.90 : x
  2. Step 2: Convert to fraction form
    413.70/619.20 = 321.90/x
  3. Step 3: Cross multiply
    413.70x = 619.20 × 321.90
  4. Step 4: Simplify right side
    413.70x = 199,320.48
  5. Step 5: Solve for x
    x = 199,320.48/413.70
  6. Step 6: Final answer
    x = 481.80

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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.