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Finding the Fourth Proportional to 409.20, 613.80 and 214.80

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Solution

The fourth proportional to 409.20, 613.80 and 214.80 is: 322.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.20 : 613.80 = 214.80 : x
  2. Step 2: Convert to fraction form
    409.20/613.80 = 214.80/x
  3. Step 3: Cross multiply
    409.20x = 613.80 × 214.80
  4. Step 4: Simplify right side
    409.20x = 131,844.24
  5. Step 5: Solve for x
    x = 131,844.24/409.20
  6. Step 6: Final answer
    x = 322.20

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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.