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Finding the Fourth Proportional to 408.84, 612.88 and 213.80

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Solution

The fourth proportional to 408.84, 612.88 and 213.80 is: 320.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.84 : 612.88 = 213.80 : x
  2. Step 2: Convert to fraction form
    408.84/612.88 = 213.80/x
  3. Step 3: Cross multiply
    408.84x = 612.88 × 213.80
  4. Step 4: Simplify right side
    408.84x = 131,033.74
  5. Step 5: Solve for x
    x = 131,033.74/408.84
  6. Step 6: Final answer
    x = 320.50

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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.