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Finding the Fourth Proportional to 408.21, 611.65 and 253.86

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Solution

The fourth proportional to 408.21, 611.65 and 253.86 is: 380.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.21 : 611.65 = 253.86 : x
  2. Step 2: Convert to fraction form
    408.21/611.65 = 253.86/x
  3. Step 3: Cross multiply
    408.21x = 611.65 × 253.86
  4. Step 4: Simplify right side
    408.21x = 155,273.21
  5. Step 5: Solve for x
    x = 155,273.21/408.21
  6. Step 6: Final answer
    x = 380.37

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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.