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Finding the Fourth Proportional to 408.78, 613.20 and 134.76

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Solution

The fourth proportional to 408.78, 613.20 and 134.76 is: 202.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.78 : 613.20 = 134.76 : x
  2. Step 2: Convert to fraction form
    408.78/613.20 = 134.76/x
  3. Step 3: Cross multiply
    408.78x = 613.20 × 134.76
  4. Step 4: Simplify right side
    408.78x = 82,637.64
  5. Step 5: Solve for x
    x = 82,637.64/408.78
  6. Step 6: Final answer
    x = 202.16

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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.