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Finding the Fourth Proportional to 409.20, 613.56 and 135.21

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Solution

The fourth proportional to 409.20, 613.56 and 135.21 is: 202.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.20 : 613.56 = 135.21 : x
  2. Step 2: Convert to fraction form
    409.20/613.56 = 135.21/x
  3. Step 3: Cross multiply
    409.20x = 613.56 × 135.21
  4. Step 4: Simplify right side
    409.20x = 82,959.45
  5. Step 5: Solve for x
    x = 82,959.45/409.20
  6. Step 6: Final answer
    x = 202.74

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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.